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NGC 6530 XMM-Newton X-Ray Point Source Catalog
This table contains the results of a 20 ks XMM-Newton observation of the Lagoon Nebula (M 8). The EPIC images of this region reveal a cluster of point sources, most of which have optical counterparts inside the very young open cluster NGC 6530. The bulk of these X-ray sources are probably associated with low and intermediate mass pre-main sequence stars. One of the sources experienced a flare-like increase of its X-ray flux making it the second brightest source in M 8 after the O4 star 9 Sgr. The X-ray spectra of most of the brightest sources can be fitted with thermal plasma models with temperatures of kT ~ a few keV. Only a few of the X-ray selected PMS candidates are known to display H-alpha emission and were previously classified as classical T Tauri stars. This suggests that most of the X-ray emitting PMS stars in NGC 6530 are weak-line T Tauri stars. In addition to 9 Sgr, the EPIC field of view contains also a few early-type stars. This table contains information on 117 of the 119 X-ray sources (2 sources, a point source associated with 9 Sgr and an extended source associated with the Hourglass Nebula were excluded from this table by the authors) that were detected using the SAS source detection algorithms in the soft band (0.5 - 1.2 keV) of an EPIC observation of 9 Sgr which have either a combined likelihood >= 20 and are detected in the individual images from all 3 EPIC instruments with -ln p_i >= 3.0 or (in two cases) where clearly detected in 2 of the 3 instruments but fell outside of the FOV of the third. The faintest sources in this category have about 10-3 cts s<sup>-1</sup> over the 0.5 - 1.2 keV band of the MOS instruments. Assuming a 1 keV thermal spectrum with a neutral hydrogen column density of 0.17 x 10<sup>22</sup> cm<sup>-2</sup>, the faintest sources correspond to an observed flux of about 8.9 x 10<sup>-15</sup> erg cm<sup>-2</sup> s<sup>-1</sup> and an unabsorbed flux of 13.1 x 10<sup>-15</sup> erg cm<sup>-2</sup> s<sup>-1</sup> in the 0.5 - 5.0 keV energy range. Note that the corresponding observed flux in the 0.5 - 1.2 keV soft band would be 5.2 x 10<sup>-15</sup> erg cm<sup>-2</sup> s<sup>-1</sup>. 72 X-ray sources have a single optical counterpart from the Sung et al (2000, <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/AJ/120/333">CDS Cat. <J/AJ/120/333></a>) catalog or in the SIMBAD database within a radius of less than 9 arcsec. The average angular separation between the X-ray source and the optical counterpart is 4.1 +/- 2.1 arcseconds. 17 X-ray sources have two or more optical stars falling within the 9 arcsec radius. Seven of these sources have at least one known H-alpha emission star inside their error box. 28 sources do not have an optical counterpart in the catalogue of Sung et al. The authors have cross-correlated these sources with the Guide Star Catalog and, in most cases, they find one or several GSC objects inside the 9 arcsec radius. These optical counterparts are usually very faint (V or R >=17) except for sources 91, 92 and 94 that have counterparts with R magnitudes 15.0, 14.6 and 13.3 respectively (note that these sources fall outside the area investigated by Sung et al.). Sources 93, 96, 98, 99, 100, 101, 102 and 112 have no GSC counterpart. Most of the objects in Table 3 are therefore X-ray sources with high X-ray to visual luminosity ratios. Given the galactic coordinates of NGC 6530 (l_II = 6.14, b_II = -1.38), the total galactic column density along this line of sight must be extremely large and the number of extragalactic sources in the soft detection energy band should be extremely low. This table was created by the HEASARC in March 2007 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/395/499">CDS catalog J/A+A/395/499</a> files table1.dat, table2.dat and table3.dat. This is a service provided by NASA HEASARC .
IC 348 Chandra X-Ray Point Source Catalog 2
IC 348 is a nearby (~ 310 pc), young (~ 2 - 3 Myr) open cluster with > 300 members identified from optical and infrared observations. The authors studied the properties of the coronae of the young low-mass stars in IC 348, combining X-ray and optical/infrared data. The four existing Chandra observations of IC 348 were merged, thus providing a deeper and spatially more complete X-ray view than previous X-ray studies of the cluster. The authors compiled a comprehensive catalog of IC 348 members taking into account recent updates to the cluster census. Their data collection comprises fundamental stellar parameters, infrared excess indicating the presence of disks, H-alpha emission as a tracer of chromospheric emission or accretion, and mass accretion rates. The authors have detected 290 X-ray sources in four merged Chandra exposures, of which 185 are associated with known cluster members corresponding to a detection rate of ~ 60% for the cluster members of IC 348 identified in optical/infrared studies. According to the most recent spectral classification of IC 348 members, only four of the X-ray sources are brown dwarfs (spectral type M6 and later). The detection rate is highest for diskless Class III stars and increases with stellar mass. This may be explained with higher X-ray luminosities for higher mass and later evolutionary stage that is evident in the X-ray luminosity functions. In particular, the authors find that for the lowest examined masses (0.1 M<sub>sun</sub> - 0.25 M<sub>sun</sub>) there is a difference between the X-ray luminosity functions of accreting and non-accreting stars (classified on the basis of their H-alpha emission strength) as well as those of disk-bearing and diskless stars (classified on the basis of the slope of the spectral energy distribution). These differences disappear for higher masses. This is related to the finding that the L<sub>x</sub>/L<sub>bol</sub> ratio is non-constant across the mass/luminosity sequence of IC 348 with a decrease towards lower luminosity stars. Their analysis of an analogous stellar sample in the Orion Nebula Cluster suggests to the authors that the decline of L<sub>x</sub>/L<sub>bol</sub> for young stars at the low-mass end of the stellar sequence is likely universal. X-ray fluxes are presented for all (185) known optical/infrared IC348 members which were observed and detected by Chandra. The basic source parameters for all X-ray sources, i.e., including an additional 105 sources not associated with known IC 348 members, are given. The X-ray flux upper limits for 129 IC 348 members which were observed but not detected by Chandra (present in the as published version of Table 3 from the reference paper) are not included in this HEASARC representation of the data given in Tables 3 and 7 from the reference paper. Thus, this table contains 290 (185 + 105) rows, one for each X-ray source (IC 348 member or not) detected by Chandra in the direction of IC 348. This HEASARC table was created in February 2012 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/537/A135">CDS Catalog J/A+A/537/A135</a> files table3.dat and table7.dat. It lists the X-ray counts and other properties for the 290 Chandra X-ray sources which were listed in table7.dat. It does not include the X-ray flux upper limits for 129 non-detected IC 348 members which were given in table3.dat, so only the X-ray fluxes and luminosities for the 185 X-ray detected IC 348 members given in table3.dat are included in this table. Notice that in the CDS version there were 2 duplicate entries in table3.dat. Some of the values for the name parameter in the HEASARC's implementation of this table were corrected in April 2018. This is a service provided by NASA HEASARC .
Chandra Extended Deep Field South Survey Point Source Catalog
This table contains the combined point-source catalogs for the Extended Chandra Deep Field- South (E-CDF-S) survey. The E-CDF-S consists of four contiguous 250 ks Chandra observations covering an approximately square region of total solid angle ~0.3 square degrees, which flank the existing ~1 Ms Chandra Deep Field-South (CDF-S). The survey reaches sensitivity limits of ~1.1 x 10<sup>-16</sup> and ~6.7 x 10<sup>-16</sup> ergs cm<sup>-2</sup> s<sup>-1</sup> for the 0.5-2.0 and 2-8 keV bands, respectively. 762 distinct X-ray point sources are detected within the E-CDF-S exposure; 589 of these sources are new (i.e., not previously detected in the ~1 Ms CDF-S). This brings the total number of X-ray point sources detected in the E-CDF-S region to 915 (via the E-CDF-S and ~1 Ms CDF-S observations). Source positions are determined using matched-filter and centroiding techniques; the median positional uncertainty is ~0.35". The basic X-ray and optical properties of these sources indicate a variety of source types, although absorbed active galactic nuclei (AGNs) seem to dominate. In addition to the main Chandra catalog, this table contains the supplementary source catalog with 33 lower-significance X-ray point sources that have bright optical counterparts (R < 23 mag). These sources generally have X-ray-to-optical flux ratios expected for normal and starburst galaxies, which lack a strong AGN component. The basic number-count results for the main Chandra catalog are in good agreement with the ~1 Ms CDF-S for sources with 0.5-2.0 and 2-8 keV fluxes greater than 3 x 10<sup>-16</sup> and 1 x 10<sup>-15</sup> ergs cm<sup>-2</sup> s<sup>-1</sup>, respectively. This HEASARC table contains 809 entries: 762 entries corresponding to the 762 sources listed in the main catalog (Table 2 of the published paper), 14 sources from the cross-field source list (Table 3) which give properties for sources which were detected in more than one observational sources, e.g. there are two entries for the source with source_number = 367, one entry coming from the main catalog, the other entry from the cross-field catalog, and 33 entries corresponding to the 33 sources in the supplementary, optically bright source catalog (Table 6). The HEASARC has created a new parameter called source_type to identify from which of these 3 original tables any given entry comes from; it is set to 'main', 'crossfield' and 'supplement' for entries from Tables 2, 3, and 6, respectively. This online catalog was created by the HEASARC in January 2006 based on machine-readable versions of tables 2, 3, and 6 from the paper which were obtained from the ApJ website. This is a service provided by NASA HEASARC .
NGC 2264 Chandra X-Ray Point Source Catalog 2
With the goal of improving the member census of the NGC 2264 star-forming region and studying the origin of X-ray activity in young pre-main sequence (PMS) stars, the authors analyzed a deep, 100 ks long, Chandra ACIS observation covering a 17' x 17' field in the 3 Myr old star-forming region (SFR) NGC 2264. The preferential detection in X-rays of low-mass PMS stars gives strong indications of their membership. The authors study X-ray activity as a function of stellar and circumstellar characteristics by correlating the X-ray luminosities, temperatures, and absorptions with optical and near-infrared (NIR) data from the literature. The authors detected 420 X-ray point sources in the observation above a 4.6-sigma significance threshold using the PWDetect software. Optical and NIR counterparts were found in the literature for 85% of the sources. The authors argue that more than 90% of these counterparts are NGC 2264 members, thereby significantly increasing the known low-mass cluster population by about 100 objects. Among the sources without counterpart, about 50% are probably associated with members, several of which are expected to be previously unknown protostellar objects. With regard to activity, several previous findings are confirmed: X-ray luminosity is related to stellar mass, although with a large scatter; L<sub>x</sub>/L<sub>bol</sub> is close to, but almost invariably below, the saturation level of 10<sup>-3</sup>, especially when considering the quiescent X-ray emission. A comparison between classical T Tauri stars (CTTS) and weak-line T Tauri stars (WTTS) shows several differences: CTTS have, at any given mass, activity levels that are both lower and more scattered than WTTS; emission from CTTS may also be more time variable and is on average slightly harder than for WTTS. However, there is evidence in some CTTS of extremely cool, ~0.1 - 0.2 keV, plasma which the authors speculate is due to plasma heated by accretion shocks. The X-ray spectra of the 199 sources with more than 50 detected photons were analyzed by the authors. Spectral fits were performed with XSPEC 11.3 and with several shell and TCL scripts to automate the process. For each source, they fit the data in the [0.5 - 7.0] keV energy interval with several model spectra: one and two isothermal components (APEC), subject to photoelectric absorption from interstellar and circumstellar material (WABS). Plasma abundances for one-temperature (1T) models were fixed at 0.3 times the solar abundances, while they were both fixed at that value and treated as a free parameter for the two-temperature (2T) models. The absorbing column densities, N<sub>H</sub>, were both left as a free parameter and fixed at values corresponding to the optically/NIR determined extinctions, when available: N<sub>H</sub> = 1.6 x 10<sup>21</sup> A<sub>V</sub>. This table contains the X-ray, optical and NIR data for the 420 detected X-ray sources; it does not contain the master catalog of 1598 optical/NIR sources within the ACIS FOV which was presented in Table 3 of the reference paper, available at <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/455/903/table3.dat">https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/455/903/table3.dat</a> This table was created by the HEASARC in March 2007 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/455/903">CDS Catalog J/A+A/455/903</a> files table1.dat, table4.dat and table6.dat. This is a service provided by NASA HEASARC .
CG 12 Chandra X-Ray Point Source Catalog
The mysterious high Galactic latitude cometary globule CG 12 has been observed with the ACIS detector on board the Chandra X-Ray Observatory. 128 X-ray sources are detected, of which half are likely young stars formed within the globule's head. This new population of >~ 50 T Tauri stars and one new embedded protostar is far larger than the previously reported few intermediate-mass and two protostellar members of the cloud. Most of the newly discovered stars have masses of 0.2-0.7 M<sub>solar</sub>, and 9% - 15% have K-band excesses from inner protoplanetary disks. X-ray properties provide an independent distance estimate consistent with the unusual location of CG 12 >~200 pc above the Galactic plane. The star formation efficiency in CG 12 appears to be 15% - 35%, far above that seen in other triggered molecular globules. The median photometric age found for the T Tauri population, assuming Siess et al. (2000, A&A, 358, 593) isochrones, is ~4 Myr with a large spread of <1 - 20 Myr and ongoing star formation in the molecular cores. The stellar age and spatial distributions are inconsistent with a simple radiation-driven implosion (RDI) model and suggest either that CG 12 is an atypically large shocked globule or that it has been subject to several distinct episodes of triggering and ablation. In their paper the authors report a previously unnoticed group of B-type stars northwest of CG 12 that may be the remnants of an OB association that produced multiple supernova explosions that could have shocked and ablated the cloud over a 15 - 30 Myr period. HD 120958 (B3e), the most luminous member of the group, may be currently driving an RDI shock into the CG 12 cloud. The current project combines four X-ray observations of the globule: <pre> Field ObsID Start Time Expo. R.A. Decl. Roll Angle (UT) (ks) (J2000.0) (deg) I.... 6423 2006 Apr 15 16:19:17 30.8 13 57 44.52 39 58 48.31 11.5 II... 6424 2006 Jun 02 07:25:09 3.1 13 57 42.87 39 43 01.76 285.0 III.. 6425 2006 Apr 13 08:44:08 3.1 13 56 19.40 39 42 47.94 14.7 IV... 6426 2006 Apr 15 12:54:20 3.1 13 56 19.40 39 58 48.09 11.1 </pre> where the units of right ascension are hours, minutes, and seconds, and the units of declination are degrees, arcminutes, and arcseconds, ObsID values are from the Chandra Observation Catalog, exposure times are the sum of Good Time Intervals (GTIs) for the CCD at the telescope aim point (CCD3) minus 1.3% to account for CCD readouts, and the aim points and roll angles are obtained from the satellite aspect solution before astrometric correction was applied. There is one primary field (I in Fig. 1 of the reference paper) with ~31 ks exposure directed at the globule's core and three secondary fields (II, III, and IV in Fig. 1) with ~3 ks exposures positioned contiguously to the north and west of the core. The primary pointing is intended to detect the population of pre-main sequence (PMS) stars forming in the molecular head of the globule. The secondary pointings are designed to locate an older population of stars expected if the present cloud is only the ablated remnant of a larger cloud that experienced sequential star formation triggering events, similar to the sequence of stars found in the authors' Chandra study of IC 1396N (Getman et al. 2007, ApJ, 654, 316, available in Browse as the IC1396NCXO table). Source searching was performed with data images and exposure maps constructed at three spatial resolutions (0.5", 1.0", and 1.4" pixel<sup>-1</sup>) using the CIAO wavdetect tool. The authors ran wavdetect with a low threshold P = 10<sup>-5</sup>, which is highly sensitive but permits false detections at this point in the analysis. This was followed by visual examination to locate other candidate sources, mainly close doubles and candidate sources near the detection threshold. Using ACIS Extract, photons were extracted within polygonal contours of ~90% encircled energy using position-dependent models of the PSF. The background was measured locally in source-free regions. Due to the very low, spatially invariant ACIS-I background in the Chandra observations of CG 12, there is a one-to-one correspondence between a source's significance and net counts. Following the procedure of Getman et al. (2007, ApJ, 654, 316), the list of candidate sources ws trimmed to omit sources with fewer than ~5 estimated source net counts, net full-band counts/PSF fraction <~ 4.5. In the case of the CG 12 observations, the above criterion is equivalent to accepting sources with a source significance of >~ 1.1. Thus, most of the statistically insignificant source candidates found during the wavdetect step were eliminated by the application of these source existence criteria. For Chandra sources with > 20 net counts, the authors performed spectral analysis with the XSPEC spectral fitting package version 12.2. The unbinned source and background spectra were fitted
LAT 2-year Point Source Catalog
The Fermi Gamma-ray Space Telescope (Fermi) Large Area Telescope (LAT) is a successor to EGRET, with greatly improved sensitivity, resolution, and energy range. This web page presents the second full catalog of LAT sources, based on the first 24 months of survey data. For a full explanation about the catalog and its construction see the LAT 2-year Catalog Paper (also available on arxiv).
Midcourse Space Experiment (MSX) Point Source Catalog, V2.3
This table contains the main catalog from Version 2.3 of the Midcourse Space Experiment (MSX) Point Source Catalog (PSC), which supersedes the previous version (1.2) that was released in 1999, and contains 100,000 more sources than the latter. The MSX PSC main catalog used to create this Browse table contains all the sources found in the Galactic Plane survey, and the primary high-latitude regions (the IRAS gaps regions, and the Large Magellanic Cloud). Note that this HEASARC table does not contain the MSX PSC supplementary catalogs, viz. the singleton catalog, the low-reliability catalog, or the minicatalogs for 19 selected regions. The principal objective of the astronomy experiments onboard the MSX satellite was to complete the census of the mid-infrared (4.2-25 micron or um) sky: namely, the areas missed by the IRAS mission (about 4% of the sky was not surveyed by IRAS), and the Galactic Plane (where the sensitivity of IRAS was degraded by confusion noise in regions of high source densities or of structured extended emission). The photometry is based on co-added image plates, as opposed to single-scan data, which results in improved sensitivity and hence reliability in the fluxes. Comparison with Tycho-2 positions indicates that the astrometric accuracy of the new catalog is more than 1" better than that in Version 1.2. The infrared instrument on MSX was named SPIRIT III; it was a 35-cm clear aperture off-axis telescope with five line scanned infrared focal-plane arrays of 18.3 arcseconds square pixels, with a high sensitivity (0.1 Jy at 8.3 um). The filter characteristics of the 6 spectral bands B1, B2, A, C, D and E are summarized below, where all wavelengths are in micron (µm): <pre> Band Center FWHM Points ---------------------------- B1 4.29 um 4.22 - 4.36 um B2 4.35 4.24 - 4.45 A 8.28 6.8 - 10.8 C 12.13 11.1 - 13.2 D 14.65 13.5 - 15.9 E 21.34 18.2 - 25.1 </pre> The MSX catalog names of the sources have been defined according to International Astronomical Union (IAU) conventions with a unique identifier combined with the position of the source. In this case, the MSX PSC V2.3 sources are named using the convention MSX6C GLLL.llll+/-BB.bbbb, where MSX6C denotes that this is MSX data run using Version 6.0 of the CONVERT software, and GLLL.llll+/-BB.bbbb gives the Galactic coordinates of the source. This database table was first created by the HEASARC in November 2002 and then updated in April 2005, based on the 11-Dec-2003 version of the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/V/114">CDS Catalog V/114</a> (specifically, the files gb_gt6.dat, gp_m05m2.dat, gp_m2m6.dat, gp_p05p2.dat, gp_p2p6.dat, and gp_pm05.dat which comprise the main catalog). This is a service provided by NASA HEASARC .
Kappa Orionis XMM-Newton X-Ray Point Source Catalog
X-rays are a powerful probe of activity in the early stages of star formation. They allow us to identify young stars even after they have lost the IR signatures of circumstellar disks and provide constraints on their distance. Here, the authors report on XMM-Newton observations that detected 121 young stellar objects (YSOs) in two fields between the filamentary dark cloud complex Lynds 1641S and the star Kappa Ori. These observations extend the Survey of Orion A with XMM and Spitzer (SOXS). The YSOs are contained in a ring of gas and dust apparent at millimeter wavelengths, and in far-IR and near-IR surveys. The X-ray luminosity function of the YSOs detected in the two fields indicates a distance of 250-280 pc, much closer than the Orion A cloud and similar to the distance estimates for Kappa Ori. The authors propose that the ring is a 5-8 pc diameter shell that has been swept up by Kappa Ori. This ring contains several groups of stars detected by Spitzer and WISE including one surrounding the Herbig Ae/Be star V1818 Ori. In this interpretation, the Kappa Ori ring is one of several shells swept up by massive stars within the Orion Eridanus Superbubble and is unrelated to the southern portion of Orion A/L 1641S. The XMM-Newton observations consist of two fields, north (Field N = KN) and south (Field S = KS), and were obtained in 2015 March 10 and 15 using EPIC as the primary instrument. Table 1 in the reference paper shows the details of the exposures, each one with a duration of about 50 ks and taken with the Medium filter. The authors used SAS version 14.0 to reduce the observation data files (ODFs) and to obtain calibrated lists of events for the MOS and pn instruments. They filtered the events in the 0.3-0.8 keV energy band and used only events with FLAG = 0 and PATTERN < 12 as prescribed by the SAS manual. With SAS, the authors obtained exposure maps in the 0.3-8.0 keV band and performed source detection with a code based on wavelet convolution that operated simultaneously on MOS and pn data. They used a threshold of significance of 4.5 sigma of the local background to discriminate real sources from spurious background fluctuations. However, they added few sources to the final list with significance S in 4.0 < S < 4.5 for the cases of positional match with objects in SIMBAD or PPMX catalogs. The final list was also checked for spurious sources that could appear at the border of the CCDs. In sum, the authors detected 238 X-ray sources with significance > 4 sigma of the local background; 104 sources are in KN and 134 in KS. The authors cross-correlated the positions of the X-ray sources with the coordinates of the IR catalog of Megeath et al. (2012, AJ, 144, 192). This IR catalog is the result of a survey of Orion with Spitzer that produced a classification of protostars and stars with disks. Of the 238 X-ray sources, 191 are identified within 8 arcseconds of one of 206 IR objects, 99 sources in KS, 92 sources in KN. Some X-ray sources were multiple matches within 8 arcsec of IR objects. For these cases, the authors assigned the most likely counterparts based on IR photometry and visual inspection of X-rays and IR images. However, nine X-ray sources were left associated with two or three IR objects. Among the IR matches, the authors found 15 stars with disks in KN and 35 in KS with X-ray detection. One protostar in KN and three in KS were detected in X-rays. The authors used X-ray detection of sources without IR excess as criteria to identify disk-less stars (hereafter Class III stars). They classified as Class III stars those IR objects with X-ray detections, with [4.5um]-[8.0um] colors < 0.3 mag and brighter than [4.5um] magnitude < 14. At the distance of the ONC (400 pc), the [4.5um] magnitude ~ 14 threshold at an age of 4-5 Myrs roughly identifies M3-M4 spectral types and masses around 0.3 solar masses. With this selection scheme, the authors identified 48 objects in KN and 19 in KS as Class III candidates. This table was created by the HEASARC in August 2016 based on the electronic version of Table 2 from the reference paper which was obtained from the CDS (their catalog J/ApJ/820/L28 file table2.dat). This is a service provided by NASA HEASARC .
IC 348 Chandra X-Ray Point Source Catalog
The authors have obtained a deep (53 ks) X-ray image of the very young stellar cluster IC 348 with the Advanced CCD Imaging Spectrometer on board the Chandra X-Ray Observatory. In this image with a sensitivity limit of ~ 1 x 10<sup>28</sup> ergs/s (more than 10 times deeper than their ROSAT images of IC 348), 215 X-ray sources were detected. While 115 of these sources can be identified with known cluster members, 58 X-ray sources are most likely new, still unidentified cluster members. About 80% of all known cluster members with masses between ~0.15 and 2 solar masses are visible as X-ray sources in the ACIS image. X-ray emission at levels of ~10<sup>28</sup> ergs/s was discovered from four of 13 known brown dwarfs and from three of 12 brown dwarf candidates in IC 348. X-ray emission was also detected from two deeply embedded objects, presumably class I protostars, south of the cluster center. Optical and infrared counterparts have been identified for most of the X-ray sources. Some 40 X-ray sources do not have optical or IR counterparts, and are most likely background (probably extragalactic) objects. This number is consistent with the expected number of extragalactic background X-ray sources based on the observed log N - log S statistics from the deep X-ray counts in the Chandra Deep Field South. This table was created by the HEASARC in January 2007 based on the merger of CDS table J/AJ/122/866/table1.dat (Table 1 from Preibisch and Zinnecker 2001) with the electronic AJ table version of Table 1 from Preibisch and Zinnecker 2002. This is a service provided by NASA HEASARC .
SnowEx20 CRREL Terrestrial Laser Scanner (TLS) Point Cloud V001
This data set contains terrestrial LIDAR survey (TLS) point cloud data collected at Grand Mesa, Colorado as part of the 2020 SnowEx campaign. Data were collected in fall 2019 (September) and winter 2020 (January and February). Each data file contains X, Y, and Z coordinates (Easting, Northing, and Elevation), along with ancillary information, such as intensity (i) and color (R,G,B), where available.
INTEGRAL Public Pointed Science Window Data
Because of the pointing-slew-pointing dithering-nature of INTEGRAL operations, each observation of a celestial target is actually comprised of numerous individual S/C pointings and slews. In addition, there are periods within a given sequence where scheduled observations occur, i.e., engineering windows, yet the instruments still acquire data. The INTEGRAL Science Data Center (ISDC) generalizes all of these data acquisition periods into so-called `Science Windows.' A Science Window (ScW) is a continuous time interval during which all data acquired by the INTEGRAL instruments result from a specific S/C attitude orientation state. Pointing (fixed orientation), Slew (changing orientation), and Engineering (undefined orientation) windows are all special cases of a Science Window. The key is that the same attitude information may be associated with all acquired data of a given Science Window. Note that it is possible to divide a time interval that qualifies as a Science Window under this definition into several smaller Science Windows using arbitrary criteria. The INTEGRAL Public Pointed Science Window Data Catalog is a subset of the INTEGRAL Science Window Data Catalog. It only includes pointed science windows that have non-private proprietary status and at least one instrument's "good" exposure time greater than zero. This database table was first created at the HEASARC in October 2004. It is a slightly modified mirror of the online database maintained by the ISDC at the URL <a href="http://isdc.unige.ch/index.cgi?Data+browse">http://isdc.unige.ch/index.cgi?Data+browse</a> <p> The HEASARC version of this table is updated automatically within a day of the ISDC updating their database table. This is a service provided by NASA HEASARC .
IC 10 Chandra X-ray Point Source Catalog
The authors monitored the Cassiopeia dwarf galaxy (IC 10) in a series of 10 Chandra ACIS-S observations to capture its variable and transient X-ray source population, which is expected to be dominated by High Mass X-ray Binaries (HMXBs). They present a sample of 21 X-ray sources that are variable between observations at the 3-sigma level, from a catalog of 110 unique point sources (the HEASARC notes that there are actually 111 sources in the CDS version of the catalog from which this HEASARC table originates). The authors find four transients (flux variability ratio greater than 10) and a further eight objects with ratios >5. The observations span the years 2003-2010 and reach a limiting luminosity of >10<sup>35</sup> erg/s, providing sensitivity to X-ray binaries in IC 10 as well as flare stars in the foreground Milky Way. The nature of the variable sources is investigated from light curves, X-ray spectra, energy quantiles, and optical counterparts. The purpose of this study is to discover the composition of the X-ray binary population in a young starburst environment. IC 10 provides a sharp contrast in stellar population age (<10 million years) when compared to the Magellanic Clouds (40-200 Myr) where most of the known HMXBs reside. The authors find 10 strong HMXB candidates, 2 probable background active galactic nuclei, 4 foreground flare-stars or active binaries, and 5 not yet classifiable sources. Complete classification of the sample requires optical spectroscopy for radial velocity analysis and deeper X-ray observations to obtain higher S/N spectra and search for pulsations. A catalog (contained in this HEASARC table) has been created and supporting data sets (the data used to create the light curves shown in Figures 3, 4 and 5 in the reference paper) are available at <a href="http://cdsarc.u-strasbg.fr/ftp/cats/J/ApJ/836/50/">http://cdsarc.u-strasbg.fr/ftp/cats/J/ApJ/836/50/</a>. A monitoring series of 7x15 ks Chandra/ACIS observations, spaced at roughly six-week intervals was obtained during 2009-2010. A pair of very deep ACIS-S3 observations (2x45ks) made in 2006 November provided a reference data set for improved source positions and spectral information. The original Wang+ (2005, MNRAS, 362, 1065) Chandra (ACIS-S3) observation of 30 ks made in 2003 was also included in this analysis. The complete listing of 10 Chandra observation identifiers (ObsIDs) comprising the data set is summarized in Table 1 of the reference paper, also shown here: <pre> MJD |Date |ObsID|Flag|Exp.|RA(J2000)Dec(J2000)|Roll|Num. Sources ks hh mm ss dd mm ss deg. 52710.7|2003 Mar 12 |03953|a |28.9|00 20 25 +59 16 55|339.27|31 54041.8|2006 Nov 2 |07082| |40.1|00 20 04 +59 16 45|223.70|48 54044.2|2006 Nov 5 |08458| |40.5|00 20 04 +59 16 45|223.70|41 55140.7|2009 Nov 5 |11080| |14.6|00 20 17 +59 17 56|226.53|19 55190.2|2009 Dec 25 |11081| | 8.1|00 20 19 +59 18 02|286.15|24 55238.5|2010 Feb 11 |11082| |14.7|00 20 23 +59 17 10|320.56|24 55290.6|2010 Apr 4 |11083| |14.7|00 20 34 +59 19 01| 10.32|25 55337.8|2010 May 21 |11084| |14.2|00 20 25 +59 20 16| 67.89|27 55397.5|2010 Jul 20 |11085| |14.5|00 20 11 +59 19 13|121.25|22 55444.6|2010 Sep 5 |11086| |14.7|00 20 15 +59 18 11|157.71|27 |2006 Nov 2-5 |57082|b |80.6|00 20 04 +59 16 45|223.70|63 </pre> Flag values as follows: <pre> a = ObsID 03953 used about half of the CCD area in subarray mode. b = Merged 2006 data set referred to as ObsID 57082 consists of the nearly contiguous ObsIDs 07082 and 08458, which had identical pointings. </pre> Roll is the spacecraft roll angle, and Num. Sources is the number of unique point sources detected in each observation after combining wavdetect lists from the soft (S: 0.3-1.5 keV), broad (B: 0.3-8 keV) and hard (H: 2.5-8 keV) energy bands. This table was created by the HEASARC in November 2017 based upon the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJ/836/50">CDS Catalog J/ApJ/836/50</a> file table2.dat. This is a service provided by NASA HEASARC .
NGC 5866 Chandra X-Ray Point Source Catalog
S0 galaxies are often thought to be passively evolved from spirals after star formation is quenched. To explore what is actually occurring in such galaxies, the authors conducted a multi-wavelength case study of NGC 5866 - a nearby edge-on S0 galaxy in a relatively isolated environment. This study shows strong evidence for dynamic activities in the interstellar medium, which are most likely driven by supernova explosions in the galactic disk and bulge. Understanding these activities can have strong implications for studying the evolution of such galaxies. The authors utilized Chandra, Hubble Space Telescope, and Spitzer data as well as ground-based observations to characterize the content, structure, and physical state of the medium and its interplay with the stellar component in NGC 5866. These reveal the presence of diffuse X-ray-emitting hot gas, which extends as far as 3.5 kpc away from the galactic plane and can be heated easily by Type Ia SNe in the bulge. The Chandra/ACIS observation of NGC 5866 was taken on 2002 November 14. The authors reprocessed the archived data for their study. See Figure 1 in the reference paper for the Chandra/ACIS-S image of NGC 5866 in the 0.3-7 keV band. This table contains the detected X-ray point sources listed in table 2 of this paper. This table was created by the HEASARC in May 2018 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJ/706/693">CDS Catalog J/ApJ/706/693</a> file table2.dat, the list of detected X-ray sources in the Chandra observation of NGC 5866. This is a service provided by NASA HEASARC .
LAT 2-year Point Source Catalog
The Fermi Gamma-ray Space Telescope (Fermi) Large Area Telescope (LAT) is a successor to EGRET, with greatly improved sensitivity, resolution, and energy range. This web page presents the second full catalog of LAT sources, based on the first 24 months of survey data. For a full explanation about the catalog and its construction see the LAT 2-year Catalog Paper (also available on arxiv).
S254-S258 Star-Forming Region Chandra X-Ray Point Source Catalog
The aim of this study was to find an explanation for the remarkable morphology of the central part of the S254-S258 star forming complex. The authors performed a deep Chandra X-ray observation of the S254-S258 region in order to efficiently discriminate young stars (with and without circumstellar matter) from the numerous older field stars in the area. They detected 364 X-ray point sources in a 17' x 17' (~ 8 x 8 pc) field. This X-ray catalog provides, for the first time, a complete sample of all young stars in the region down to about 0.5 M_{sun}_. A clustering analysis identifies three significant clusters: the central embedded cluster S255-IR and two smaller clusterings in S256 and S258. Sixty-four X-ray sources can be classified as members in one of these clusters. After accounting for X-ray background contaminants, this implies that about 250 X-ray sources constitute a widely scattered population of young stars, distributed over the full field-of-view of the X-ray image. This distributed young stellar population is considerably larger than the previously known number of non-clustered young stars selected by infrared excesses. Comparison of the X-ray luminosity function with that of the Orion Nebula Cluster suggests a total population of ~ 2000 young stars in the observed part of the S254-S258 region. The S254-S258 complex was observed (PI: Preibisch) in November 2009 with the Imaging Array of the Chandra Advanced CCD Imaging Spectrometer (ACIS-I). ACIS-I provides a field of view of 17' x 17' on the sky. At the 1.6 kpc distance of S254-S258 this corresponds to 7.9 x 7.9 pc. The aimpoint of the observation was RA(J2000) = 06h12m54.0s, Dec(J2000) = +17d 59' 24". The observation was performed in the standard 'Timed Event, Faint' mode (with 3 x 3 pixel event islands). The total net exposure time of 74725 s (20.76 h) was split into two parts, separated by about 4 days. The details of these two observation parts are given in Table 1 of the reference paper. The authors first employed the wavdetect algorithm (Freeman et al. 2002, ApJS, 138, 185, a CIAO mexican-hat wavelet source detection tool) for locating X-ray sources in the merged image, and used a rather low detection threshold of 10<sup>-5</sup>. This step was performed in three different energy bands, the total band (0.5 - 8.0 keV), the soft band (0.5 - 2.0 keV), and the hard band (2.0 - 8.0) keV, and with wavelet scales between 1 and 16 pixels. They also performed a visual inspection of the images and added some 30 additional candidates to the merged catalog from the wavelet analysis, resulting in a final catalog of 511 potential X-ray sources. To clean this catalog from spurious sources, they then performed a detailed analysis of each individual candidate source with the ACIS Extract (AE hereafter) software package (Broos et al. 2010, ApJ, 714, 1582). The Poisson probability (P<sub>B</sub>) associated with the "null hypothesis", i.e. that no source exists and the extracted events are solely due to Poisson fluctuations in the local background, was computed for each source using AE. All candidate sources with P<sub>B</sub> > 0.01 were rejected as background fluctuations. After 8 iterations of this pruning procedure the final catalog consisted of 364 sources. It contains 344 primary sources with P<sub>B</sub> < 0.003, and 20 tentative sources with 0.003 < P<sub>B</sub> < 0.01. To obtain an estimate of the intrinsic, i.e. extinction-corrected, X-ray luminosity for sources that are too weak for a detailed spectral analysis, the authors used the XPHOT software, developed by Getman et al. (2010, ApJ, 708, 1760). XPHOT is based on a non-parametric method for the calculation of fluxes and absorbing X-ray column densities of weak X-ray sources. X-ray extinction and intrinsic flux are estimated from the comparison of the apparent median energy of the source photons and apparent source flux with those of high signal-to-noise spectra that were simulated using spectral models characteristic of much brighter sources of similar class previously studied in detail. This method requires at least 4 net counts per source (in order to determine a meaningful value for the median energy) and can thus be applied to 255 of the 364 sources in this table. To calculate luminosities, a distance of 1.6 kpc was assumed. The resulting intrinsic X-ray lumonosities range from 10<sup>29.4</sup> to 10<sup>32.3</sup> erg s<sup>-1</sup>. This table was created by the HEASARC in October 2011 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/533/A121">CDS Catalog J/A+A/533/A121</a> files table2.dat, table3.dat and table5.dat. This is a service provided by NASA HEASARC .
Cepheus A SFR XMM-Newton X-Ray Point Source Catalog
Cepheus A is a star formation region (SFR) at a distance of ~ 730 pc consisting of two main H II regions, Cep A East and Cep A West. Cep A was observed with the EPIC cameras of the XMM-Newton observatory on 2003 August 23 for 43.9ks. In this observation, X-rays from both components of Cep A, East and West, were discovered by XMM-Newton, as well as from the Herbig-Haro object HH 168, which joins the ranks of other energetic H-H objects that are sources of temperature T >= 10<sup>6</sup> K X-ray emission. A total of 102 distinct X-ray sources were detected in this 44 ks observation, many presumed to be pre-main-sequence stars on the basis of the reddening of their optical and IR counterparts, the latter being found by matching the positions of the 102 X-ray sources with objects in the USNO-B1.0 (Monet et al. 2003, AJ, 125, 984) and Two Micron All Sky Survey (2MASS) catalogs using a 2.5" matching radius. The authors performed source detection on all the XMM-Newton data in two energy bands: 0.2 - 1 keV ("soft") and 1 - 10 keV ("hard"). They detected 24 soft sources and 85 hard sources. Seven of the sources appear in both bands, where the criterion for a match between the bands is a positional offset of < 2.5 arcseconds. Thus, the total number of distinct X-ray sources detected (and listed in this table) is 102. This table was created by the HEASARC in July 2007 based on the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJ/626/272">CDS Catalog J/ApJ/626/272</a> file table2.dat. This is a service provided by NASA HEASARC .
Chandra Galactic Bulge Survey Full X-Ray Point Source Catalog
This table contains the Chandra source list for the entire area of the Galactic Bulge Survey (GBS) based on the lists provided in Jonker et al. (2011, ApJ, 194, 18: Paper I) and Jonker et al. (2014, ApJS, 210, 18: Paper II). The previous version of this table, based solely on the data presented in Paper I, contained the Chandra source list based on the first three-quarters of the GBS that had been observed as of the date of writing of that paper. Among the goals of the GBS are constraining the neutron star (NS) equation of state and the black hole (BH) mass distribution via the identification of eclipsing NS and BH low-mass X-ray binaries (LMXBs). The latter goal will, in addition, be obtained by significantly enlarging the number of BH systems for which a BH mass can be derived. Further goals include constraining X-ray binary formation scenarios, in particular the common envelope phase and the occurrence of kicks, via source-type number counts and an investigation of the spatial distribution of X-ray binaries, respectively. The GBS targets two strips of 6 degrees by 1 degrees (12 deg<sup>2</sup> in total), one above (1<sup>o</sup> < b < 2<sup>o</sup>) and the other below (-2<sup>o</sup> < b < -1<sup>o</sup>) the Galactic plane in the direction of the Galactic center at X-ray, optical and near-infrared wavelengths. By avoiding the Galactic plane (-1<sup>o</sup> < b < 1<sup>o</sup>) the authors limit the influence of extinction on the X-ray and optical emission but still sample relatively large number densities of sources. The survey is designed such that a large fraction of the X-ray sources can be identified from their optical spectra. The X-ray survey, by design, covers a large area on the sky while the depth is shallow, using 2 ks per Chandra pointing. In this way, the authors maximize the predicted number ratio of (quiescent) LMXBs to cataclysmic variables. The survey is approximately homogeneous in depth to a 0.5-10 keV flux of 7.7 x 10<sup>-14</sup> erg cm<sup>-2</sup> s<sup>-1</sup>. As of Paper I, the authors had covered about three-fourths (8.3 deg<sup>2</sup>) of the projected survey area with Chandra observations providing 1234 unique X-ray sources. In Paper II, the authors find 424 additional X-ray sources in the 63 Chandra observations that they report on there. In the papers, the authors discuss the characteristics and the X-ray variability of the brightest of the sources as well as the radio properties from existing radio surveys. They point out an interesting asymmetry in the number of X-ray sources as a function of their Galactic l and b coordinates which is probably caused by differences in average extinction towards the different parts of the GBS survey area. This table was originally ingested by the HEASARC in June 2011 based on an electronic version of Table 3 from Paper I which was obtained from the ApJS web site. The current version of this table was ingested by the HEASARC in January 2014 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJS/210">CDS catalog J/ApJS/210</a>,18 file cxogbs.dat, which appears to be the combination of an Table 3 from Paper I with Table 1 from Paper II. This is a service provided by NASA HEASARC .
SDSS-IV/SPIDERS XMM-Based X-Ray Point Source Spectroscopic Catalog
This catalog aims to provide a detailed description of the SPectroscopic IDentification of ERosita Sources (SPIDERS) survey, an SDSS-IV program aimed at obtaining spectroscopic classification and redshift measurements for complete samples of sufficiently bright X-ray sources. The authors describe the SPIDERS X-Ray Point Source Spectroscopic Catalog, considering its store of 11,092 observed spectra drawn from a parent sample of 14,759 ROSAT and XMM sources over an area of 5,129 deg<sup>2</sup> covered in SDSS-IV by the eBOSS survey. This catalog presents the SPIDERS XMM subsample of 3,196 sources which were drawn from the XMM Slew Survey source catalog, version 2 (XMMSL2), provided by the HEASARC in <a href="/W3Browse/xmm-newton/xmmslewful.html">XMMSLEWFUL</a>. The accompanying <a href="/W3Browse/rosat/spidersros.html">SPIDERSROS</a> table contains the 21,288 sources drawn from the Second ROSAT All-Sky Survey (2RXS) Source Catalog, available from the HEASARC as <a href="/W3Browse/rosat/rass2rxs.html">RASS2RXS</a>. This program represents the largest systematic spectroscopic observation of an X-ray selected sample. A total of 10,970 (98.9%) of the observed objects are classified and 10,849 (97.8%) have secure redshifts. The majority of the spectra (10,070 objects) are active galactic nuclei (AGN), 522 are cluster galaxies, and 294 are stars. The SDSS-IV/BOSS spectrographic observations are taken between 2014 and 2019. This table was created by the HEASARC in May 2020 based upon the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/636/A97">CDS Catalog J/A+A/636/A97</a> file vcxmmsl2.dat. This is a service provided by NASA HEASARC .
Dose-dependent skeletal deficits due to varied reductions in mechanical loading in rats (Femur - microCT, three-point bending, histomorphometry)
Reduced skeletal loading leads to marked bone loss. Animal models of hindlimb suspension are widely used to assess alterations in skeleton during the course of complete unloading. More recently, the effects of partial unloading on the musculoskeletal system have been interrogated in mice and rats, revealing dose-dependent effects of partial weight bearing (PWB) on the skeleton and skeletal muscle. Here, we extended these studies to determine the structural and functional skeletal alterations in 14-week-old male Wister rats exposed to 20%, 40%, 70%, or 100% of body weight for 1, 2, or 4 weeks (n equals 11–12/group). Using in vivo pQCT, we found that trabecular bone density at the proximal tibia declined in proportion to the degree of unloading and continued progressively with time, without evidence of a plateau by 4 weeks. Ex vivo measurements of trabecular microarchitecture in the distal femur by microcomputed tomography revealed deficits in bone volume fraction, 2 and 4 weeks after unloading. Histologic analyses of trabecular bone in the distal femur revealed the decreased osteoblast number and mineralizing surface in unloaded rats. Three-point bending of the femoral diaphysis indicated modest or no reductions in femoral stiffness and estimated modulus due to PWB. Our results suggest that this rat model of PWB leads to trabecular bone deterioration that is progressive and generally proportional to the degree of PWB, with minimal effects on cortical bone. This study derives results from the Mechanical Testing, Bone Microstructure (microCT), and bone histomorphometry assays using femur tissue.
NGC 2362 Chandra X-Ray Point Source Catalog
This table contains the results of an observation of the young cluster NGC 2362 in X-rays with Chandra ACIS-I in which 387 point X-ray sources, most of which are shown to be cluster members, were detected using PWDetect, a wavelet-based source detection algorithm, with a detection threshold chosen to ensure no more than one spurious detection in the entire ACIS FOV. The table lists all of the detected X-ray sources and their basic X-ray properties, as well as their proposed identifications with optical stars, using data from Moitinho et al. (2001ApJ...563L..73M; UBVRI photometry) and Dahm (2005, <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/AJ/130/1805">CDS Cat. <J/AJ/130/1805></a>; H-alpha data), as well as newer photometric data from Moitinho et al. (2005, in 'Cores to Clusters' [A&SSL, 324], 167). A matching position of less than 4 times the X-ray positional uncertainty of the X-ray source from PWDetect was used. Also included in the table is a classification of the optically-identified X-ray sources, based on their positions in the HR Diagram, which helps to separate rather clearly the cluster members from interloping field objects. This table was created by the HEASARC in March 2007 based on CDS table J/A+A/460/133 files table2.dat and table3.dat. This is a service provided by NASA HEASARC .
ScienceDex guides
Understand access before you commit
These curated guides explain access requirements, typical timelines, costs, and reuse considerations for widely used research datasets.
Allen Brain Atlas
Allen Brain Atlas is an Allen Institute collection of brain map atlases, datasets, APIs, and analysis tools covering mouse, human, and non-human primate brain resources.
Annotated Behaviour and Observability Dataset (ABODe)
ABODe is a University of Edinburgh DataShare dataset for behavior classification in group-housed mice using home-cage video, identities, bounding boxes, ground-plate positions, and annotator labels.
DANDI Archive for NWB datasets
DANDI is a BRAIN Initiative archive for publishing and sharing neurophysiology data, including electrophysiology, optophysiology, and behavioral data packaged as NWB and related standards.
International Brain Laboratory public data
The International Brain Laboratory public data releases expose standardized mouse decision-making experiments, including Neuropixels recordings, widefield calcium imaging, behavior, and session metadata accessed through the ONE API.
OpenNeuro
OpenNeuro is a free, open platform for sharing neuroimaging datasets, with public search, dataset pages, and download paths for web, S3, DataLad, and the OpenNeuro CLI.