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45 results for “Survey of galaxies”

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zenodo32/100

Data for "The Massive and Distant Clusters of WISE Survey. XII. Exploring X-ray AGN in Dynamically Active Massive Galaxy Clusters at z~1"

<p>This dataset corresponds to the manuscript titled "The Massive and Distant Clusters of <em>WISE</em> Survey. XII. Exploring X-ray AGN in Dynamically Active Massive Galaxy Clusters at z~1" (<span>DOI: 10.3847/1538-4357/adbae4)</span>, accepted for publication in <em>The Astrophysical Journal</em> on February 24, 2025. To replicate the plots and access the catalogs used in the paper, download and extract all the zip folders along with the Jupyter Notebook "<a href="https://zenodo.org/api/records/14928038/draft/files/madcows_notebook.ipynb/content">madcows_notebook.ipynb</a>" into the same directory. Open the notebook and follow the instructions provided. For any issues, please contact the corresponding author.</p>

opencc-by-4.0Apr 2024View details →
zenodo32/100

Generating mock galaxy catalogues for flux-limited samples like the DESI Bright Galaxy Survey

<p>Supplementary material to DESI's publication "Generating mock galaxy catalogues for flux-limited samples like the DESI Bright Galaxy Survey" to comply with the data management plan. This includes the Python scripts and data points required to reproduce all figures in the publication.</p>

opencc-by-4.0Jun 2024View details →
zenodo32/100

Data for DESI Publication DESI-2022-0160: DESI Survey Validation Spectra Reveal an Increasing Fraction of Recently Quenched Galaxies at z~1

<p>This folder contains all the data on figures for DESI Publication&nbsp;DESI-2022-0160, which is about to be sent to final reading.</p>

opencc-by-4.0Nov 2022View details →
zenodo24/100

Star formation and morphological properties of galaxies in the P\lowercase{an}-STARRS 3$\pi$ survey- I.\\ A machine learning approach to galaxy and supernova classification

<pre>This is the catalog presented in Baldeschi, et al (2020). The catalog is subdivided in 13 csv files. Files description: First column: Panstar ID (integer) Second column: Right ascension [deg] (float) Third column: Declination [deg] (float) Fourth column: Probability for a source of being a star (P_star) (float) Fifth column: Probability for a galaxy of being higly star-forming (P_HSFF) (float) Sixth column: Probability for a galaxy of being spiral (P_spiral) (float) seventh column: Compleatness flag (string) If using this catalog for publications, please cite Baldeschi, et al (2020). Fourth column values are from Tachibana &amp; Miller (2018). For a detailed description of the columns we refer to the Appendix A of Baldeschi, et al (2020).</pre>

opencc-by-4.0Jul 2020View details →
nasa20/100

Spitzer Survey of Stellar Structure in Galaxies Catalog

The Spitzer Survey of Stellar Structure in Galaxies (S4G) is a volume-, magnitude-, and size-limited survey of over 2300 nearby galaxies at 3.6 and 4.5 microns. This is an extremely deep survey reaching an unprecedented 1 sigma surface brightness limit of μ3.6(AB) = 27 mag arcsec-2. This translates to a stellar surface density of << 1 Msun pc-2.The S4G Catalog provides photometry and model parameters derived from the IRAC images, as well as a link to the summary and data access page for each galaxy and a variety of quantities taken from previously published work.

restrictednotspecifiedApr 2025View details →
nasa20/100

ROSAT All-Sky Survey Bright Source Catalog/Catalog of Principal Galaxies Matches

In a correlation study of the ROSAT All-Sky Survey Bright Source Catalog (RASS-BSC, &lt;a href="https://cdsarc.cds.unistra.fr/ftp/cats/XI/10"&gt;CDS Cat. &lt;XI/10&gt;&lt;/a&gt;, the HEASARC table RASSBSC) with the Catalogue of Principal Galaxies (PGC, &lt;a href="https://cdsarc.cds.unistra.fr/ftp/cats/VII/119"&gt;CDS Cat. &lt;VII/119&gt;&lt;/a&gt;, the HEASARC table PGC2003), 904 X-ray sources were found that possess possible extragalactic counterparts within a search radius of 100 arcseconds. A visual screening process was applied to classify the reliability of the correlations. 547 correlations have been quoted as reliable identifications. From these, 349 sources are known to be active galaxies. Although for the other sources no hints for activity were found in the literature, 69% of those for which we have distances show X-ray luminosities exceeding those of normal galaxies, a clear sign that these galaxies also own hitherto unreported X-ray active components. Some objects are located inside or in the direction of a known group or cluster of galaxies. Their X-ray flux may therefore be in part affected by hot gas emission. In the paper, luminosity and log N-log S distributions are used to characterize different subsamples. Nuclei that are both optically and X-ray active are found predominantly in spirals. Two special source samples are defined, one with candidates for X-ray emission from hitherto unknown groups or clusters of galaxies, and one with high X-ray luminosity sources, that are likely candidates to possess hitherto unreported active galactic nuclei. Besides a compilation of X-ray and optical parameters, X-ray overlays on optical images for all the objects are also supplied as part of this work. This table contains 1124 optical galaxy entries for the 904 relevant X-ray candidates/counterparts from the RASS. Besides a compilation of X-ray and optical parameters for each source, the results of an identification screening are also given. The 904 optical images with X-ray overlay contours (xID_nnn.ps.gz) used in the screening process are added for each user&#39;s own judgement of the reliability of the associations. This table was created by the HEASARC in March 2012 based on &lt;a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/378/30"&gt;CDS catalog J/A+A/378/30&lt;/a&gt; file table1.dat, the list of PGC galaxies identified as possible counterparts to RASS Bright Source Catalog X-ray sources. This is a service provided by NASA HEASARC .

restrictednotspecifiedApr 2025View details →
nasa20/100

6dFGS Galaxy Survey Final Redshift Release Catalog

The final redshift release of the 6dF Galaxy Survey (6dFGS) is a combined redshift and peculiar velocity survey over the southern sky (|b| &gt; 10 degrees). Its 136,304 spectra have yielded 110,256 new extragalactic redshifts and a new catalogue of 125,071 galaxies making near-complete samples with limits in (K, H, J, r&lt;sub&gt;F&lt;/sub&gt;, b&lt;sub&gt;J&lt;/sub&gt;) (12.65, 12.95, 13.75, 15.60, 16.75). The median redshift of the survey is 0.053. The catalog includes basic data for the galaxies in the 6dFGS with redshifts, using the best 6dFGS redshifts (radial velocity quality flag Q =3 or 4) plus available redshifts from SDSS, 2dFGRS and ZCAT (124,647 entries in all). It supersedes the previous DR2 version (&lt;a href="https://cdsarc.cds.unistra.fr/ftp/cats/VII/249"&gt;CDS Cat. VII/249&lt;/a&gt;). The home page of of the 6dFGS database is &lt;a href="http://www-wfau.roe.ac.uk/6dFGS"&gt;http://www-wfau.roe.ac.uk/6dFGS&lt;/a&gt;. Any use of these data should explicitly state that they come from the Final Release of 6dFGS and cite both the 6dGS DR3 paper (Jones et al. 2009, MNRAS, 399, 683) as well as the original 6dFGS survey paper (Jones et al. 2004, MNRAS, 355, 747). This table was created by the HEASARC in March 2011 based on &lt;a href="https://cdsarc.cds.unistra.fr/ftp/cats/VII/259"&gt;CDS Catalog VII/259&lt;/a&gt; file 6dfgs.dat. This is a service provided by NASA HEASARC .

restrictednotspecifiedApr 2025View details →
nasa20/100

Sloan Digital Sky Survey DR6 Galaxy Clusters Catalog

Clusters of galaxies in most of the previous catalogs have redshifts z &lt;= 0.3. Using the photometric redshifts of galaxies from the Sloan Digital Sky Survey Data Release 6 (SDSS DR6), the authors identify 39,716 clusters in the redshift range 0.05 &lt; z &lt; 0.6 with more than eight luminous (M_r &lt;= -21) member galaxies. Cluster redshifts are estimated accurately with an uncertainty of less than 0.022. The contamination rate of member galaxies is found to be roughly 20%, and the completeness of member galaxy detection reaches ~90%. Monte Carlo simulations show that the cluster detection rate is more than 90% for massive (M_200 &gt; 2 x 10&lt;sup&gt;14&lt;/sup&gt; M_sun, where M_200 is the total mass within the radius in which the mean mass density is 200 times the critical cosmic mass density) clusters of z &lt;= 0.42. The false detection rate is ~5%. The authors obtain the richness, the summed luminosity, and the gross galaxy number within the determined radius for identified clusters. They are tightly related to the X-ray luminosity and temperature of the clusters. Cluster mass is related to the richness and summed luminosity with M_200 ~ R&lt;sup&gt;(1.90+/-0.04)&lt;/sup&gt; and M_200 ~ L_r&lt;sup&gt;(1.64+/-0.03)&lt;/sup&gt;, respectively. In addition, 790 new candidate X-ray clusters are found by cross-identification of these clusters with the source list of the ROSAT X-ray All-Sky Survey. This table was created by the HEASARC in August 2009 based on electronic versions of Tables 1 and 2 from the paper which were obtained from the Astrophysical Journal web site. This is a service provided by NASA HEASARC .

restrictednotspecifiedApr 2025View details →
nasa20/100

2XMMi/SDSS Galaxy Cluster Survey Extension

This table contains results from the analysis of a sample of 383 X-ray selected galaxy groups and clusters with spectroscopic redshift measurements (up to z ~ 0.79) from the 2XMMi/SDSS Galaxy Cluster Survey. The X-ray cluster candidates were selected as serendipitously detected sources from the 2XMMi-DR3 catalog that were located in the footprint of the Sloan Digital Sky Survey (SDSS-DR7). The cluster galaxies with available spectroscopic redshifts were selected from the SDSS-DR10. The authors developed an algorithm for identifying the cluster candidates that are associated with spectroscopically targeted luminous red galaxies and for constraining the cluster spectroscopic redshift. A cross-correlation of the constructed cluster sample with published optically selected cluster catalogs yielded 264 systems with available redshifts. The present redshift measurements (presented in reference paper III) are consistent with the published values. The current cluster sample extends the optically confirmed cluster sample from the authors&#39; cluster survey by 67 objects. Moreover, it provides spectroscopic confirmation for 78 clusters among their published cluster sample, which previously had only photometric redshifts. Of the new cluster sample that comprises 67 systems, 55 objects are newly X-ray discovered clusters and 52 systems are sources newly discovered as galaxy clusters in optical and X-ray wavelengths. Based on the measured redshifts and the fluxes given in the 2XMMi-DR3 catalogue, the authors have estimated the X-ray luminosities and masses of the cluster sample. This table contains 145 entries, 67 of which are new (as of Paper III) optically confirmed clusters (marked by values of ref_source = &#39;Paper III&#39;) and 78 of which are clusters from Paper II which have now been spectroscopically confirmed (marked by values of ref_source = &#39;Paper II&#39;). The tabular information on the 530 clusters that was presented in Paper II of this set of papers is available as the HEASARC &lt;a href="/W3Browse/xmm-newton/xmmsdssgcs.html"&gt;XMMSDSSGCS table&lt;/a&gt;). The following parameters were obtained from the current optical-band cluster detection algorithm: sdss_dr10_bcg_id, sdss_dr10_bcg_ra, sdss_dr10_bcg_dec, bcg_rmag, redshift, num_spect_members, phot_redshift, num_phot_members, and spatial_offset. This table was created by the HEASARC in July 2014 based on &lt;a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/564/A54"&gt;CDS catalog J/A+A/564/A54&lt;/a&gt; file table1.dat. This is a service provided by NASA HEASARC .

restrictednotspecifiedApr 2025View details →
nasa20/100

Faint Sky Variability Survey Catalog of Galaxy Clusters and Rich Groups

The Faint Sky Variability Survey Catalog of Galaxy Clusters and Rich Groups contains a a large sample of 598 galaxy clusters and rich groups discovered in the data of the Faint Sky Variability Survey (FSVS). The clusters have been identified using a fully automated, semi-parametric technique based on a maximum likelihood approach applied to Voronoi tessellation, and enhanced by color discrimination. The sample covers a wide range of richness, has a density of ~28 clusters per square degree, and spans a range of estimated redshifts of 0.05 &lt; z &lt; 0.9 with mean &lt;z&gt; = 0.345. Assuming the presence of a cluster red sequence, the uncertainty of the estimated cluster redshifts is assessed to be sigma ~ 0.03. Containing over 100 clusters with z &gt; 0.6, the catalog contributes substantially to the current total of optically-selected, intermediate-redshift clusters, and complements the existing, usually X-ray selected, samples. The FSVS fields are accessible for observation throughout the whole year, making them particularly suited for large follow-up programs. The construction of this FSVS Cluster Catalogue completes a fundamental component of the authors&#39; continuing program to investigate the environments of quasars and the chemical evolution of galaxies. The present table contains the list of all clusters with their basic parameters. This table was created by the HEASARC in July 2006 based on the table cluster_catalogue.txt copied from the first author&#39;s website &lt;a href="https://web.archive.org/web/20100318044103/www-astro.physics.ox.ac.uk/~iks/FSVScatalogue/"&gt;https://web.archive.org/web/20100318044103/www-astro.physics.ox.ac.uk/~iks/FSVScatalogue/&lt;/a&gt; (no longer available, unfortunately). Refer instead to &lt;a href="https://cdsarc.unistra.fr/viz-bin/cat/J/MNRAS/369/1334"&gt;https://cdsarc.unistra.fr/viz-bin/cat/J/MNRAS/369/1334&lt;/a&gt; for the data files and to &lt;a href="https://www.noao.edu/survey-archives/fsvs/"&gt;https://www.noao.edu/survey-archives/fsvs/&lt;/a&gt; for additional information about the survey. This is a service provided by NASA HEASARC .

restrictednotspecifiedApr 2025View details →
nasa20/100

ROSAT-ESO Flux-Limited X-Ray (REFLEX) Galaxy Cluster Survey

This table is the ROSAT-ESO Flux-Limited X-Ray (REFLEX) Galaxy Cluster Survey Catalog. The REFLEX Cluster Survey provides information on the X-ray properties, redshifts, and some identification details of clusters in the REFLEX sample. The catalog describes a statistically complete X-ray flux-limited sample of 447 galaxy clusters above an X-ray flux of 3 x 10&lt;sup&gt;-12&lt;/sup&gt; erg/s/cm&lt;sup&gt;2&lt;/sup&gt; (0.1 to 2.4 keV) in an area of 4.24 steradians in the southern sky. The cluster candidates were first selected by their X-ray emission in the ROSAT-All Sky Survey and subsequently spectroscopically identified in the frame of an ESO key program. Previously described tests have shown that the sample is more than 90% complete and there is a conservative upper limit of 9% on the fraction of clusters with a dominant X-ray contamination from AGN. This data set is at present the largest, statistically complete X-ray galaxy cluster sample. The sample forms the basis of several cosmological studies, one of the most important applications being the assessment of the statistics of the large-scale structure of the universe and the test of cosmological models. The X-ray luminosities and other distance-dependent cluster parameters are calculated for a Lambda cosmology with a Hubble Constant H&lt;sub&gt;0&lt;/sub&gt; of 70 km/s/Mpc, Omega&lt;sub&gt;M&lt;/sub&gt; of 0.3, and Omega&lt;sub&gt;Lambda&lt;/sub&gt; of 0.7. The CDS version of this catalog contains an additional table (reflex50.dat) with these parameters calculated for an Einstein-de Sitter universe with H&lt;sub&gt;0&lt;/sub&gt; = 50 km/s/Mpc, Omega&lt;sub&gt;M&lt;/sub&gt; = 1.0, and Omega&lt;sub&gt;Lambda&lt;/sub&gt; = 0.0. This table was created by the HEASARC in October 2004 based on CDS tables J/A+A/425/367/reflex70.dat and J/A+A/425/367/reflex.dat. This is a service provided by NASA HEASARC .

restrictednotspecifiedApr 2025View details →
nasa20/100

Einstein Survey of Optically Selected Galaxies

The Einstein Survey of Optically Selected Galaxies contains the results of a complete Einstein Imaging Proportional Counter (IPC) X-ray survey of optically-selected galaxies from the Shapley-Ames (S-A) Catalog (CDS Catalog &lt;VII/112&gt;), the Uppsala General Catalog (UGC, &lt;a href="https://cdsarc.cds.unistra.fr/ftp/cats/VII/26"&gt;CDS Catalog &lt;VII/26&gt;&lt;/a&gt;) and the European Southern Observatory (ESO) Catalog (&lt;a href="https://cdsarc.cds.unistra.fr/ftp/cats/VII/115"&gt;CDS Catalog &lt;VII/115&gt;&lt;/a&gt;). Well-defined optical criteria were used to select the galaxies, and X-ray fluxes were measured at the optically-defined positions. The result is a comprehensive list of X-ray detection and upper limit measurements for 1018 galaxies. Of these, 827 galaxies have either independent distance estimates or radial velocities. Associated optical, redshift, and distance data have been assembled for these galaxies, and their distances come from a combination of directly predicted distances and those predicted from the Faber-Burstein Great Attractor/Virgocentric infall model. The accuracy of the X-ray fluxes has been checked in three different ways; all are consistent with the derived X-ray fluxes being of &lt;= 0.1 dex accuracy. In particular, there is agreement with previously published X-ray fluxes for galaxies in common with a 1991 study by Roberts et al. (1991ApJS...75..751R) and a 1992 study by Fabbiano et al. (1992ApJS...80..531F, also available at the HEASARC as a database table called EINGALCAT). This database was created at the HEASARC in May 2002 based on the ADC/&lt;a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJS/111/163"&gt;CDS Catalog J/ApJS/111/163&lt;/a&gt; and is derived from Tables 5, 6, 7, 12, 13, and 14 of the published paper. This is a service provided by NASA HEASARC .

restrictednotspecifiedApr 2025View details →
nasa20/100

Second Byurakan Survey General Catalog Galaxies Optical Database

The Second Byurakan Survey (SBS) is a continuation of the First Byurakan Survey (FBS), also known as the Markarian Survey. The goal of the SBS was to reach fainter objects (as faint as limiting photographic magnitudes of 19.5, about 2.5 magnitudes fainter than the Markarian survey) and discover new active and star-forming galaxies using both UV excess and emission-line techniques. In this table, a database for the entire catalog of the Second Byurakan Survey (SBS) galaxies is presented, i.e, the 1700 SBS stars listed in Stepanian (2005) are not included herein. It contains new measurements of their optical parameters and additional information taken from the literature and other databases. The measurements were made using I&lt;sub&gt;pg&lt;/sub&gt; (near-infrared), F&lt;sub&gt;pg&lt;/sub&gt; (red) and J&lt;sub&gt;pg&lt;/sub&gt; (blue) band images from photographic sky survey plates obtained by the Palomar Schmidt telescope and extracted from the STScI Digital Sky Survey (DSS). The database provides accurate coordinates, morphological type, spectral and activity classes, apparent magnitudes and diameters, axial ratios, and position angles, as well as number counts of neighboring objects in circles of radii 50 kpc around the sources. The total number of individual SBS objects in the database is now 1676. The 188 Markarian galaxies which were re-discovered by the SBS are not included in this database. the authors also include redshifts that are now available for 1576 SBS objects, as well as 2MASS infrared magnitudes for 1117 SBS galaxies. The new optical information on the SBS galaxies was obtained from images extracted from the STScI Digitized Sky Survey (DSS) of F_pg (red), J_pg (blue) and I_pg (near-infared) band photographic sky survey plates obtained by the Palomar telescope. This table was created by the HEASARC in May 2012 based on &lt;a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/VII/264"&gt;CDS Catalog J/VII/264&lt;/a&gt; file sbs.dat. This is a service provided by NASA HEASARC .

restrictednotspecifiedApr 2025View details →
nasa20/100

ROSAT All-Sky Survey CALS Galaxy Groups Catalog

This table contains the catalog from the ROSAT All-Sky Survey (RASS) Center for Astrophysics (CfA) Loose Systems, or RASSCALS, the largest X-ray and optical survey of low-mass galaxy groups as of its publication date in 2000. The authors drew 260 groups from the combined Center for Astrophysics and Southern Sky Redshift Surveys, covering one-quarter of the sky to a limiting Zwicky magnitude of m&lt;sub&gt;z&lt;/sub&gt; = 15.5. They detected 61 groups (23%) as extended X-ray sources. The X-ray detections have a median membership of nine galaxies, a median recession velocity cz = 7250 km/s, a median projected velocity dispersion sigma(p) = 400 km/s, and a median X-ray luminosity L(x) = 3 x 10&lt;sup&gt;42&lt;/sup&gt; /h(100)&lt;sup&gt;2&lt;/sup&gt; erg/s, where the Hubble constant is H(0) = 100 h(100) km/s/Mpc. The data in this table replace the preliminary analysis of the X-ray data which was presented in Mahdavi et al., 1999, ApJ, 518, 69 (CDS Cat. &lt;J/ApJ/518/69&gt;. This table was created by the HEASARC in September 2005 based on CDS tables J/ApJ/534/114/table2.dat &amp; table3.dat. This is a service provided by NASA HEASARC .

restrictednotspecifiedApr 2025View details →
nasa20/100

DEEP2 Galaxy Redshift Survey Fields Chandra Point Source Catalog

This table contains the X-ray point-source catalog produced from the Chandra Advanced CCD Imaging Spectrometer (ACIS-I) observations of the combined ~3.2 deg&lt;sup&gt;2&lt;/sup&gt; DEEP2 (XDEEP2) survey fields, which consist of four ~ 0.7 - 1.1 deg&lt;sup&gt;2&lt;/sup&gt; fields. The combined total exposures across all four XDEEP2 fields range from ~ 10 ks to 1.1 Ms. The authors detect X-ray point sources in both the individual ACIS-I observations and the overlapping regions in the merged (stacked) images. They find a total of 2976 unique X-ray sources within the survey area with an expected false-source contamination of ~ 30 sources (&lt;~ 1%). In their paper, the authors present the combined log N-log S distribution of sources detected across the XDEEP2 survey fields and find good agreement with the Extended Chandra Deep Field and Chandra-COSMOS fields to f_(X,0.5-2keV)_ ~ 2 x 10&lt;sup&gt;-16&lt;/sup&gt; erg cm&lt;sup&gt;-1&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;. Given the large survey area of XDEEP2, they additionally place relatively strong constraints on the log N-log S distribution at high fluxes (f_(X,0.5-2keV) ~ 3 x 10&lt;sup&gt;-14&lt;/sup&gt; erg cm&lt;sup&gt;-1&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;), and find a small systematic offset (a factor ~ 1.5) toward lower source numbers in this regime, when compared to smaller area surveys. The number counts observed in XDEEP2 are in close agreement with those predicted by X-ray background synthesis models. Additionally, the authors present a Bayesian-style method for associating the X-ray sources with optical photometric counterparts in the DEEP2 catalog (complete to R&lt;sub&gt;AB&lt;/sub&gt; &lt; 25.2) and find that 2126 (~ 71.4% +/- 2.8%) of the 2976 X-ray sources presented here have a secure optical counterpart with a &lt;~ 6% contamination fraction. The present table provides the DEEP2 optical source properties (e.g., magnitude, redshift) as part of the X-ray-optical counterpart catalog. This table was created by the HEASARC in October 2012 based on electronic versions of Tables 5 and 7 from the reference paper which were obtained from the ApJS web site. This is a service provided by NASA HEASARC .

restrictednotspecifiedApr 2025View details →
nasa20/100

VST Kilo-Degree Infrared Galaxy (VIKING) Survey ConeSearch

All MAST catalog holdings are available via Cone Search endpoints. This service provides access to the MAST copy of the VST Kilo-degree Infrared Galaxy (VIKING) SurveyAll available missions are listed at http://archive.stsci.edu/vo/mast_services.html.

restrictednotspecifiedApr 2025View details →
nasa20/100

Northern ROSAT All-Sky (NORAS) Galaxy Cluster Survey Catalog

In the construction of an X-ray-selected sample of galaxy clusters for cosmological studies, the authors have assembled a sample of 495 X-ray sources which were found to show extended X-ray emission in the first processing of the ROSAT All-Sky Survey (RASS I), the Northern ROSAT All-Sky (NORAS) Galaxy Cluster Survey Catalog. The sample covers the celestial region with declination &gt;=0 degrees and Galactic latitude |b| &gt;= 20 degrees, and comprises sources with a Position Sensitive Proportional Counter (PSPC) count rate &gt;= 0.06 counts/s and a source extent likelihood of L &gt;= 7. In an optical follow-up identification program, the authors found 378 (76%) of these sources to be clusters of galaxies. It was necessary to reanalyze the sources in this sample with a new X-ray source characterization technique to provide more precise values for the X-ray flux and source extent than obtained from the standard processing. This new method, termed growth curve analysis (GCA), has the advantage over previous methods in its ability to be robust, to be easy to model and to integrate into simulations, to provide diagnostic plots for visual inspection, and to make extensive use of the X-ray data. The source parameters obtained assist the source identification and provide more precise X-ray fluxes. This reanalysis is based on data from the more recent second processing of the ROSAT Survey, RASS II. The authors present a catalog of the cluster sources with the X-ray properties obtained as well as a list of the previously flagged extended sources that are found to have a non-cluster counterpart. In their paper, they discuss the process of source identification from the combination of optical and X-ray data. To investigate the overall completeness of the cluster sample as a function of the X-ray flux limit, they extended the search for X-ray cluster sources to the RASS II data for the northern sky region between 9 and 14 hours in right ascension. They included the search for X-ray emission from known galaxy clusters as well as a new investigation of extended X-ray sources. In the course of this search, they found X-ray emission from 85 additional Abell clusters and 56 very probable cluster candidates among the newly found extended sources. A comparison of the X-ray cluster number counts of the NORAS sample with the ROSAT-ESO Flux-limited X-ray (REFLEX) Cluster Survey results leads to an estimate of the completeness of the NORAS sample of ROSAT All-Sky Survey (RASS) I extended clusters of about 50% at an X-ray flux of FX(0.1-2.4 keV) = 3 x 10-12 ergs s&lt;sup&gt;-1&lt;/sup&gt; cm&lt;sup&gt;-2&lt;/sup&gt;. The estimated completeness achieved by adding the supplementary sample in the study area amounts to about 82% in comparison to REFLEX. The low completeness introduces an uncertainty in the use of the sample for cosmological statistical studies that will be cured with the completion of the continuing Northern ROSAT All-Sky (NORAS) Cluster Survey project. This table was created by the HEASARC in June 2005 based on CDS table J/ApJS/129/435, table1.dat through table9.dat inclusive. This is a service provided by NASA HEASARC .

restrictednotspecifiedApr 2025View details →
nasa20/100

Chandra ACIS Survey of Nearby Galaxies X-Ray Point Source Catalog

The Chandra data archive is a treasure trove for various studies, and in this study the author exploits this valuable resource to study the X-ray point source populations in nearby galaxies. By 2007 December 14, 383 galaxies within 40 Mpc with isophotal major axes above 1 arcminute had been observed by 626 public ACIS observations, most of which were for the first time analyzed by this survey to study the X-ray point sources. Uniform data analysis procedures were applied to the 626 ACIS observations and led to the detection of 28,099 point sources, which belong to 17,559 independent sources. These include 8700 sources observed twice or more and 1000 sources observed 10 times or more, providing a wealth of data to study the long-term variability of these X-ray sources. Cross-correlation of these sources with galaxy isophotes led to 8,519 sources within the D&lt;sub&gt;25&lt;/sub&gt; isophotes of 351 galaxies, 3,305 sources between the D&lt;sub&gt;25&lt;/sub&gt; and 2 * D&lt;sub&gt;25&lt;/sub&gt; isophotes of 309 galaxies, and an additional 5,735 sources outside the 2 * D&lt;sub&gt;25&lt;/sub&gt; isophotes of galaxies. This survey has produced a uniform catalog, by far the largest, of 11,824 X-ray point sources within 2 * D&lt;sub&gt;25&lt;/sub&gt; isophotes of 380 galaxies. Contamination analysis using the log N-log S relation shows that 74% of the sources within the 2 * D&lt;sub&gt;25&lt;/sub&gt; isophotes above 10&lt;sup&gt;39&lt;/sup&gt; erg s&lt;sup&gt;-1&lt;/sup&gt;, 71% of the sources above 10&lt;sup&gt;38&lt;/sup&gt; erg s&lt;sup&gt;-1&lt;/sup&gt;, 63% of the sources above 10&lt;sup&gt;37&lt;/sup&gt; erg s&lt;sup&gt;-1&lt;/sup&gt;, and 56% of all sources are truly associated with the galaxies. Meticulous efforts have identified 234 X-ray sources with galactic nuclei of nearby galaxies. This archival survey leads to 300 ultraluminous X-ray sources (ULXs) with L&lt;sub&gt;X&lt;/sub&gt; in the 0.3-8 keV band &gt;= 2 x 10&lt;sup&gt;39&lt;/sup&gt; erg s&lt;sup&gt;-1&lt;/sup&gt; within the D&lt;sub&gt;25&lt;/sub&gt; isophotes, 179 ULXs between the D&lt;sub&gt;25&lt;/sub&gt; and the 2 * D&lt;sub&gt;25&lt;/sub&gt; isophotes, and a total of 479 ULXs within 188 host galaxies, with about 324 ULXs truly associated with the host galaxies based on the contamination analysis. About 4% of the sources exhibited at least one supersoft phase, and 70 sources are classified as ultraluminous supersoft sources with L&lt;sub&gt;X&lt;/sub&gt; (0.3-8 keV) &gt;= 2 x 10&lt;sup&gt;38&lt;/sup&gt; erg s&lt;sup&gt;-1&lt;/sup&gt;. With a uniform data set and good statistics, this survey enables future works on various topics, such as X-ray luminosity functions for the ordinary X-ray binary populations in different types of galaxies, and X-ray properties of galactic nuclei. This table contains the list of 17,559 &#39;independent&#39; X-ray point sources that was contained in table 4 of the reference paper. As the author notes in Section 5 of this paper, there are 341 sources projected within 2 galaxies with overlapping domains which are listed for both galaxies. The 5,735 sources lieing outside the 2* D&lt;sub&gt;25&lt;/sub&gt; isophotes of the galaxies are also included in this table. For these sources, the X-ray luminosities are computed as if they were in a galaxy of that group, which may or may not be the case; thus, they may not be their &#39;true&#39; luminosities, but are listed for the purposes of comparison. This table was created by the HEASARC in March 2011 based on the electronic version of Table 4 of the reference paper which was obtained from the Astrophysical Journal web site. Some of the values for the name parameter in the HEASARC&#39;s implementation of this table were corrected in April 2018. This is a service provided by NASA HEASARC .

restrictednotspecifiedApr 2025View details →
nasa20/100

ROSAT All-Sky Survey/6dF Galaxy Survey Catalog of X-Ray Selected AGN

This table contains a catalog of 3405 X-ray sources from the ROSAT All Sky Survey (RASS) Bright Source Catalog which fall within the area covered by the 6dF Galaxy Survey (6dFGS). The catalog is count-rate limited at 0.05 ct s&lt;sup&gt;-1&lt;/sup&gt; in the X-ray and covers the area of sky with Declination &lt; 0 degrees and |b| &gt; 10 degrees. The RASS-6dFGS sample was one of the additional target catalogs of the 6dFGS and as a result the authors obtained optical spectra for 2224 (65 per cent) RASS sources. Of these, 1715 (77%) have reliable redshifts with a median redshift of z = 0.16 (excluding the Galactic sources). For the optically bright sources (b_J &lt;= 17.5) in the observed sample, over 90% have reliable redshifts. The catalog mainly comprises quasi-stellar objects (QSOs) and active galaxies but also includes 238 Galactic sources. Of the sources with reliable redshifts, the majority are type 1 active galactic nuclei (AGN, 69%), while 12% are type 2 AGN, 6% absorption-line galaxies and 13% are stars. The authors also identify a small number of optically faint, very low redshift, compact objects which fall outside the general trend in the b_J - z plane. The RASS-6dFGS catalog complements a number of Northern hemisphere samples, particularly the ROSAT Bright Source Catalogue-NRAO VLA Sky Survey (RBSC-NVSS) sample (Bauer et al. 2000, ApJS, 129, 547), and furthermore, in the same region of sky (-40 degrees &lt; Declination &lt; 0 degrees) reveals an additional 561 sources that were not identified as part of that sample. The authors detect 918 sources (27%) of the RASS-6dFGS sample in the radio using either the 1.4 GHz NVSS or the 843 MHz Sydney University Molonglo Sky Survey (SUMSS) catalogues and find that the detection rate changes with redshift. At redshifts larger than 1 virtually all of these sources have radio counterparts and with a median flux density of 1.15 Jy, they are much stronger than the median flux density of 28.6 mJy for the full sample. The authors attribute this to the fact that the X-ray flux of these objects is being boosted by a jet component, possibly Doppler boosted, that is only present in radio-loud AGN. The RASS-6dFGS sample provides a large set of homogeneous optical spectra ideal for future studies of X-ray emitting AGN. This table was created by the HEASARC in April 2010 based on an electronic version of Table 3 from the reference paper obtained from the MNRAS web site. This is a service provided by NASA HEASARC .

restrictednotspecifiedApr 2025View details →
nasa20/100

First Byurakan Survey (Markarian) Catalog of UV-Excess Galaxies

A catalog of galaxies with UV-continuum (Markarian galaxies) detected during the First Byurakan Survey (FBS) is presented. The purpose of the FBS was to search for peculiar faint extragalactic objects with UV-excess radiation and to study them. The procedure of observations and processing, the FBS areas, the object selection and classification criteria and also several selection effects are described in the reference. The catalog contains the following initial data on all the objects: the precise coordinates, visual magnitudes, angular sizes, redshifts and classification types. The observational results of slit spectra, UBV-photometry, IR-photometry (IRAS data), morphology and some other data are also included in the catalog. While compiling the catalog, the authors introduced some necessary corrections in the data of the earlier published lists on galaxies with UV-continuum excesses. In addition, the authors included the objects with numbers 1501-1515. In most cases, they are well-known Seyfert galaxies omitted by the authors in the lists, but detected on the plates. 48 objects from their lists are not included in the catalog, since they are either stars of our Galaxy or star projections on the galaxies. This catalog presents the largest homogeneous sample of AGN of different types on the northern sky for bright objects (apparent magnitude &lt; 16.0). Up to the middle of 1987 redshifts were measured for 1459 out of 1469 objects in the catalog. This table was created by the HEASARC in November 2009 based on the electronic version of the First Byurakan Survey (Markarian galaxies catalog) which was obtained from the CDS (their catalog VII/172 file table7.dat). It replaced an earlier version of the &#39;Markarian Catalog&#39; which was based on the original galaxy lists of Markarian et al. (&lt;a href="https://cdsarc.cds.unistra.fr/ftp/cats/VII/61A"&gt;CDS catalog VII/61A&lt;/a&gt;). This is a service provided by NASA HEASARC .

restrictednotspecifiedApr 2025View details →

ScienceDex guides

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These curated guides explain access requirements, typical timelines, costs, and reuse considerations for widely used research datasets.

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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.

allen-brain-atlas
neuroscienceopenDocumentation, web resources, and API references are available online.
Last verified 2026-04-30Open record

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.

abode-home-cage
behavioral-neuroscienceopenThe DataShare record exposes download links for annotations, documentation, license text, and the zipped per-snippet data directory.
Last verified 2026-04-30Open record

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.

dandi-nwb
electrophysiologyopenPublished Dandiset metadata and archive endpoints are available through the production DANDI API.
Last verified 2026-04-30Open record

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.

ibl
behavioral-neuroscienceopenPublic sessions can be searched and loaded from the IBL public data server through ONE.
Last verified 2026-04-29Open record

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.

openneuro
neuroscienceopenPublished datasets are available on demand over the internet.
Last verified 2026-04-29Open record