- ID:
- ivo://nasa.heasarc/sacy
- Title:
- SACY (Search for Associations Containing Young Stars) Catalog
- Short Name:
- SACY
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The SACY (Search for Associations Containing Young Stars) Catalog contains the results from a high-resolution optical spectroscopic survey aimed to search for nearby young associations and young stars among optical counterparts of ROSAT All-Sky Survey X-ray sources in the Southern Hemisphere. 1953 late-type (B-V>=0.6), potentially young, optical counterparts were selected out of a total of 9574 1RXS sources for follow-up observations. At least one high-resolution spectrum was obtained for each of 1511 targets. This paper is the first in a series presenting the results of the SACY survey in which the sample of X-ray selected stars and the supporting optical observations are described. The SACY sample is defined by Hipparcos (<a href="https://cdsarc.cds.unistra.fr/ftp/cats/I/239">CDS Cat. <I/239></a>) and Tycho-2 (<a href="https://cdsarc.cds.unistra.fr/ftp/cats/I/259">CDS Cat. <I/259></a>) stars within an error radius of 2.6 times the positional error of the ROSAT All-Sky Bright Source Catalogue (1RXS, <a href="https://cdsarc.cds.unistra.fr/ftp/cats/IX/10">CDS Cat. <IX/10></a>). The used cut-off (B-V=0.6), corresponding approximately to a G0 dwarf, is near the hottest stars where the strength of the LiI line can be used as an youth indicator. All Hipparcos stars having M_v < 2.0 have been excluded. The northern boundary limits of the survey are given in Table 1 of the reference paper. In addition to the 1511 stars observed at least once, 115 stars with data taken from the literature have been added in order to complement the sample. In addition to these 1626 stars in the SACY sample (sources with source number prefixes of 'S'), entries for 165 other observed stars (sources with source number prefixes of 'O') are also included in this table. Most of the spectroscopic observations (~70%) were performed with the FEROS spectrograph at the 1.5m/ESO telescope at La Silla between January 1999 and September 2002 (ON-ESO agreement and ESO program identification 67.C-0123). Two more runs (ESO program identifications 072.C-0393 and 077.C-0138) were carried out at the 2.2m/ESO telescope. Another set of data (~30%) was collected at the coude spectrograph attached to 1.60m telescope at the Observatorio rio do Pico dos Dias (OPD), LNA, Brazil. Some spectra are a re-analysis of the ones taken for the PDS program. A few observations were collected using the CORALIE attached to the Swiss Euler Telescope at La Silla. UBV(RI)c photometry for part of the sample was obtained using FOTRAP at the 0.60m Zeiss telescope of the OPD. When a star was not observed photometrically by the authors, they tried to obtain some useful photometric data from the Hipparcos and Tycho Catalogues or in the available literature in the SIMBAD. For multiple stars, magnitudes and colors were corrected in order to take into account the presence of the companion(s). This table was created by the HEASARC in March 2007 based on the CDS table J/A+A/460/695, files table3.dat and table4.dat This is a service provided by NASA HEASARC .
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- ID:
- ivo://nasa.heasarc/sas2maps
- Title:
- SAS-2 Map Product Catalog
- Short Name:
- SAS2MAPS
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This database is a collection of maps created from the 28 SAS-2 observation files. The original observation files can be accessed within BROWSE by changing to the SAS2RAW database. For each of the SAS-2 observation files, the analysis package FADMAP was run and the resulting maps, plus GIF images created from these maps, were collected into this database. Each map is a 60 x 60 pixel FITS format image with 1 degree pixels. The user may reconstruct any of these maps within the captive account by running FADMAP from the command line after extracting a file from within the SAS2RAW database. The parameters used for selecting data for these product map files are embedded keywords in the FITS maps themselves. These parameters are set in FADMAP, and for the maps in this database are set as 'wide open' as possible. That is, except for selecting on each of 3 energy ranges, all other FADMAP parameters were set using broad criteria. To find more information about how to run FADMAP on the raw event's file, the user can access help files within the SAS2RAW database or can use the 'fhelp' facility from the command line to gain information about FADMAP. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/sas2raw
- Title:
- SAS-2 Photon Events Catalog
- Short Name:
- SAS2RAW
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The SAS2RAW database is a log of the 28 SAS-2 observation intervals and contains target names, sky coordinates start times and other information for all 13056 photons detected by SAS-2. The original data came from 2 sources. The photon information was obtained from the Event Encyclopedia, and the exposures were derived from the original "Orbit Attitude Live Time" (OALT) tapes stored at NASA/GSFC. These data sets were combined into FITS format images at HEASARC. The images were formed by making the center pixel of a 512 x 512 pixel image correspond to the RA and DEC given in the event file. Each photon's RA and DEC was converted to a relative pixel in the image. This was done by using Aitoff projections. All the raw data from the original SAS-2 binary data files are now stored in 28 FITS files. These images can be accessed and plotted using XIMAGE and other columns of the FITS file extensions can be plotted with the FTOOL FPLOT. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/sas3ylog
- Title:
- SAS-3 Y-Axis Pointed Obs Log
- Short Name:
- SAS3YLOG
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This database is the Third Small Astronomy Satellite (SAS-3) Y-Axis Pointed Observation Log. It identifies possible pointed observations of celestial X-ray sources which were performed with the y-axis detectors of the SAS-3 X-Ray Observatory. This log was compiled (by R. Kelley, P. Goetz and L. Petro) from notes made at the time of the observations and it is expected that it is neither complete nor fully accurate. Possible errors in the log are (i) the misclassification of an observation as a pointed observation when it was either a spinning or dither observation and (ii) inaccuracy of the dates and times of the start and end of an observation. In addition, as described in the HEASARC_Updates section, the HEASARC added some additional information when creating this database. Further information about the SAS-3 detectors and their fields of view can be found at: <a href="http://heasarc.gsfc.nasa.gov/docs/sas3/sas3_about.html">http://heasarc.gsfc.nasa.gov/docs/sas3/sas3_about.html</a> Disclaimer: The HEASARC is aware of certain inconsistencies between the Start_date, End_date, and Duration fields for a number of rows in this database table. They appear to be errors present in the original table. Except for one entry where the HEASARC corrected an error where there was a near-certainty which parameter was incorrect (as noted in the 'HEASARC_Updates' section of this documentation), these inconsistencies have been left as they were in the original table. This database table was released by the HEASARC in June 2000, based on the SAS-3 Y-Axis pointed Observation Log (available from the NSSDC as dataset ID 75-037A-02B), together with some additional information provided by the HEASARC itself. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/scubafemoc
- Title:
- SCUBA Legacy Fundamental and Extended Map Object Catalogs
- Short Name:
- SCUBAFEMOC
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains the SCUBA Legacy Catalogs, two comprehensive sets of source catalogs using data at 850 and 450um of the various astronomical objects obtained with the Submillimetre Common User Bolometer Array (SCUBA) on the James Clerk Maxwell Telescope (JCMT). The Fundamental Map Data Set contains data only where superior atmospheric opacity calibration data were available. The Extended Map Data Set contains data regardless of the quality of the opacity calibration. Each data set contains 1.2 degrees x 1.2 degrees maps at locations where data existed in the JCMT archive, imaged using the matrix inversion method. The Fundamental Data Set is composed of 1423 maps at 850um and 1357 maps at 450um. The Extended Data Set is composed of 1547 maps at 850um. Neither data set includes high sensitivity, single-chop SCUBA maps of "cosmological fields" nor solar system objects. Each data set was used to determine a respective object catalog, consisting of objects identified within the respective 850um maps using an automated identification algorithm. The Fundamental and Extended Map Object Catalogs contain 5061 and 6118 objects, respectively. Objects are named based on their respective J2000.0 position of peak 850um intensity. The catalogs provide for each object the respective maximum 850um intensity, estimates of total 850um flux and size, and tentative identifications from the SIMBAD Database. Where possible, the catalogs also provide for each object its maximum 450um intensity and total 450um flux and flux ratios. Since the goal of this project was to make maps and then catalog objects therein, all raw jiggle and scan data from SCUBA available in the JCMT archive were downloaded from the CADC in 2006 May. (Photometry and polarimetry data were ignored.) A full description of the instrumental characteristics of SCUBA was made by Holland et al. (1999MNRAS.303..659H). All maps are available at <a href="http://www3.cadc-ccda.hia-iha.nrc-cnrc.gc.ca/community/scubalegacy/">http://www3.cadc-ccda.hia-iha.nrc-cnrc.gc.ca/community/scubalegacy/</a> This table was created by the HEASARC in December 2010 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJS/175/277">CDS catalog J/ApJS/175/277</a> files table2.dat and table3.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/spidersros
- Title:
- SDSS-IV/SPIDERS ROSAT-Based X-Ray Point Source Spectroscopic Catalog
- Short Name:
- SPIDERSROS
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- 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 ROSAT subsample of 21,288 sources which were drawn from the Second ROSAT All-Sky Survey (2RXS), provided by the HEASARC in <a href="/W3Browse/rosat/rass2rxs.html">RASS2RXS</a>. The accompanying <a href="/W3Browse/xmm-newton/spidersxmm.html">SPIDERSXMM</a> table contains the 3,196 sources 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>. 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 vc2rxs.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/spidersxmm
- Title:
- SDSS-IV/SPIDERS XMM-Based X-Ray Point Source Spectroscopic Catalog
- Short Name:
- SPIDERSXMM
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- 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 .
- ID:
- ivo://nasa.heasarc/sdssnbckde
- Title:
- SDSS NBCKDE Catalog of Photometrically Selected Quasar Candidates
- Short Name:
- SDSSNBCKDE
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains a catalog of 1,015,082 quasar candidates selected from the photometric imaging data of the Sloan Digital Sky Survey (SDSS) using a non-parametric Bayesian classification kernel density estimator (NBC-KDE). It excludes 157,075 initial candidates that were culled as known or likely contaminants. The objects are all point sources to a limiting magnitude of i = 21.3 from 8417 deg<sup>2</sup> of imaging from SDSS Data Release 6 (DR6). This sample extends the previous catalog (Paper I: Richards et al. 2004, ApJS, 155, 257) by using the latest SDSS public release data and probing both ultraviolet (UV)-excess and high-redshift quasars. While the addition of high-redshift candidates reduces the overall efficiency (quasars:quasar candidates) of the catalog to ~80%, it is expected to contain no fewer than 850,000 bona fide quasars, which is ~8 times the number of the previous sample and ~10 times the size of the largest spectroscopic quasar catalog. Cross-matching between this photometric catalog and spectroscopic quasar catalogs from both the SDSS and 2dF survey yields 88,879 spectroscopically confirmed quasars. For judicious selection of the most robust UV-excess sources (~500,000 objects in all), the efficiency is nearly 97 - more than sufficient for detailed statistical analyses. The catalog's completeness to type 1 (broad-line) quasars is expected to be no worse than 70%, with most missing objects occurring at z < 0.7 and 2.5 < z < 3.0. In addition to classification information, the authors provide photometric redshift estimates (typically good to Delta(z) +/- 0.3 [2-sigma]) and cross-matching with radio, X-ray, and proper-motion catalogs. Finally, the authors have considered the catalog's utility for determining the optical luminosity function of quasars and are able to confirm the flattening of the bright-end slope of the quasar luminosity function at z ~ 4 as compared to z ~ 2. Much more information on the SDSS is available at the project's web site at <a href="http://www.sdss.org/">http://www.sdss.org/</a>. This table was created by the HEASARC based on an electronic version of Table 1 in the reference paper which was obtained from the ApJ web site. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/sbsggencat
- Title:
- Second Byurakan Survey General Catalog Galaxies Optical Database
- Short Name:
- SBSGGENCAT
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- 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<sub>pg</sub> (near-infrared), F<sub>pg</sub> (red) and J<sub>pg</sub> (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 <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/VII/264">CDS Catalog J/VII/264</a> file sbs.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/fermifhl
- Title:
- Second Catalog of Hard Fermi-LAT Sources (2FHL)
- Short Name:
- FERMIFHL
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This is a catalog of sources detected above 50 GeV by the Fermi-Large Area Telescope (LAT) in 80 months of data. The newly delivered Pass 8 event-level analysis allows the detection and characterization of sources in the 50GeV-2TeV energy range. In this energy band, Fermi-LAT has detected 360 sources, which constitute the second catalog of hard Fermi-LAT sources (2FHL). The improved angular resolution enables the precise localization of point sources (~1.7-arcminutes radius at 68% confidence level) and the detection and characterization of spatially extended sources. The authors found that 86% of the sources could be associated with counterparts at other wavelengths, of which the majority (75%) are active galactic nuclei and the rest (11%) are Galactic sources. Only 25% of the 2FHL sources have been previously detected by Cherenkov telescopes, implying that the 2FHL provides a reservoir of candidates to be followed up at very high energies. This work closes the energy gap between the observations performed at GeV energies by Fermi-LAT on orbit and the observations performed at higher energies by Cherenkov telescopes from the ground. This database table was first ingested by the HEASARC in September 2015 using electronic data obtained from the Fermi Science Support Center (FSSC). That data is available at <a href="http://fermi.gsfc.nasa.gov/ssc/data/access/lat/2FHL/">http://fermi.gsfc.nasa.gov/ssc/data/access/lat/2FHL/</a>. This is a service provided by NASA HEASARC .
