- ID:
- ivo://nasa.heasarc/gmrtxl610m
- Title:
- Giant Metrewave Radio Telescope XMM Large Scale Structure 610-MHz Source Catalog
- Short Name:
- GMRTXL610M
- Date:
- 18 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The low-frequency radio survey of the XMM-Large Scale Structure (XMM-LSS) field centered at RA (J2000) = 2<sup>h</sup>24<sup>m</sup>00<sup>s</sup>, Dec (J2000) = -4<sup>0</sup>09'47" aims to study the connection between the extragalactic radio source populations and their environment as traced by X-ray and optical emission. In their paper, the authors present new radio observations of the XMM-LSS field carried out using the Giant Meterwave Radio Telescope (GMRT) at 240 and 610 MHz. These observations complement the observations presented by Cohen at al. (2003, ApJ, 591, 640; <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJ/591/640">CDS Cat. <J/ApJ/591/640></a>) and Tasse et al. (2006, A&A, 456, 791; <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/456/791">CDS Cat. <J/A+A/456/791></a>) at 74 and 325 MHz with the Very Large Array (VLA). At 240 and 610 MHz, the authors reach noise levels of ~2.5 and ~0.3 mJy/beam, leading to the detection of 466 and 769 sources over 18.0 and 12.7 degree<sup>2</sup> with resolutions of 14.7 arcseconds and 6.5 arcseconds, respectively. Combining these data with the available source lists at 74 MHz, 325 MHz (Tasse et al., 2006) and 1400MHz (NVSS), the authors built a multifrequency catalog containing 1611 radio sources. They checked for consistency of the astrometry and flux density estimates. They fit a simple synchrotron radiation model to the flux density measurements of the 318 radio sources that were detected in at least 4 bands. While ~26% of them showed signature of spectral ageing, ~6% showed self absorption. This table contains the GMRT 610-MHz source list, comprising 592 single sources and 445 components of multiple sources, for a total of 1037 entries. For the multiple sources, each component (A, B, etc.) is listed separately, in order of decreasing brightness. This table was created by the HEASARC in February 2012 based on CS Catalog J/A+A/471/1105 file table4.dat. This is a service provided by NASA HEASARC .
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- ID:
- ivo://nasa.heasarc/gcscat
- Title:
- Globular Cluster Systems of Galaxies Catalog
- Short Name:
- GCSCAT
- Date:
- 18 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains a catalog of 422 galaxies with published measurements of their globular cluster (GC) populations. Of these, 248 are E galaxies, 93 are S0 galaxies, and 81 are spirals or irregulars. Among various correlations of the total number of GCs with other global galaxy properties, the authors find that the number of globular clusters N<sub>GC</sub> correlates well though nonlinearly with the dynamical mass of the galaxy bulge M<sub>dyn</sub> = 4 sigma _e_<sup>2</sup> R<sub>e</sub>/G, where sigma<sub>e</sub> is the central velocity dispersion and R<sub>e</sub> the effective radius of the galaxy light profile. In their paper, the authors also present updated versions of the GC specific frequency S<sub>N</sub> and specific mass S<sub>M</sub> versus host galaxy luminosity and baryonic mass. These graphs exhibit the previously known U-shape: highest S<sub>N</sub> or S<sub>M</sub> values occur for either dwarfs or supergiants, but in the mid-range of galaxy size (10<sup>9</sup> - 10<sup>10</sup> L<sub>sun</sub>) the GC numbers fall along a well-defined baseline value of S<sub>N</sub> ~= 1 or S<sub>M</sub> = 0.1, similar among all galaxy types. Along with other recent discussions, the authors suggest that this trend may represent the effects of feedback, which systematically inhibited early star formation at either very low or very high galaxy mass, but which had its minimum effect for intermediate masses. Their results strongly reinforce recent proposals that GC formation efficiency appears to be most nearly proportional to the galaxy halo mass M<sub>halo</sub>. The mean "absolute" efficiency ratio for GC formation that the authors derive from the catalog data is M<sub>GCS</sub>/M<sub>halo</sub> = 6 x 10<sup>-5</sup>. They suggest that the galaxy-to-galaxy scatter around this mean value may arise in part because of differences in the relative timing of GC formation versus field-star formation. Finally, they find that an excellent empirical predictor of total GC population for galaxies of all luminosities is N<sub>GC</sub> ~ (R<sub>e</sub> sigma<sub>e</sub>)<sup>1.3</sup>, a result consistent with fundamental plane scaling relations. This table was created by the HEASARC in February 2014 based on an electronic version of Table 1 from the reference paper which was obtained from the ApJ web site. A duplicate entry for NGC 4417 was removed in June 2019. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/gb6
- Title:
- Green Bank 6-cm (GB6) Radio Source Catalog
- Short Name:
- GB6
- Date:
- 18 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains the Green Bank 6-cm (GB6) Radio Source Catalog. The Green Bank 4.85 GHz (6-cm wavelength) survey (Condon J.J., Broderick J.J., Seielstad G.A., Douglas K., & Gregory P.C. in 1994AJ....107.1829C) was made with the NRAO seven-beam receiver on the (former) 91m telescope during 1986 November and 1987 October. The final set of sky maps covering the declination band 0 deg < Dec. < +75 deg was constructed with data from both epochs. Its noise and position errors are nearly a factor of 2^(1/2) smaller than in the epoch 1987 maps, from which the 87GB Catalog (<a href="https://cdsarc.cds.unistra.fr/ftp/cats/VIII/14">CDS Catalog <VIII/14></a>) of 54,579 sources stronger than S ~ 25mJy was extracted. Therefore, the new maps were used to make the GB6 catalog of 75,162 discrete sources with angular sizes phi <= 10.5 arcmin and flux densities S >= 18mJy. The GB6 weighted differential source counts S^(5/2)n(S) between 18 mJy and 7 Jy agree well with evolutionary models based on independent data. This table was created by the HEASARC in July 2003 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/VIII/40">CDS Catalog <VIII/40></a>. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/gbt31ghz
- Title:
- Green Bank Telescope 100-m 31-GHZ Radio Source Catalog
- Short Name:
- GBT31GHZ
- Date:
- 18 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The 100m Robert C. Byrd Green Bank Telescope (GBT) and the 40m Owens Valley Radio Observatory (OVRO) telescope have been used to conduct a 31-GHz survey of 3165 known extragalactic radio sources over 143 deg<sup>2</sup> of the sky. Target sources were selected from the NRAO VLA Sky Survey (NVSS) in fields observed by the Cosmic Background Imager (CBI); most are extragalactic active galactic nuclei (AGNs) with 1.4-GHz flux densities of 3-10 mJy. Using a maximum-likelihood analysis to obtain an unbiased estimate of the distribution of the 1.4 - 31 GHz spectral indices of these sources, the authors find a mean 31 - 1.4 GHz flux ratio of 0.110 +/- 0.003 corresponding to a spectral index alpha = -0.71+/-0.01 (S<sub>nu</sub> ~ nu<sup>alpha</sup>); 9.0% +/- 0.8% of the sources have alpha > -0.5 and 1.2% +/- 0.2% have alpha > 0. By combining this spectral-index distribution with 1.4GHz source counts, the authors predict 31-GHz source counts in the range 1 mJy <S<sub>31</sub> < 4 mJy, N(>S<sub>31</sub>) = (16.7+/-1.7)deg<sup>-2</sup>(S<sub>31</sub>/1mJy)<sup>(-0.80+/-0.07)</sup>. In this study, the authors present a detailed characterization of the impact of the discrete source foreground on arcminute-scale 31-GHz anisotropy measurements based upon two observational campaigns. The first campaign (the results of which are given in the OVRO31GHZ table) was carried out with the OVRO 40m telescope at 31 GHz from 2000 September through 2002 December. The second campaign (the results of which are given in the present table) used the GBT from 2006 February to May. A companion paper (Sievers et al. 2009arXiv0901.4540S) presents the five-year CBI total intensity power spectrum incorporating the results of the point-source measurements discussed here. Reported error bars include a 10% and 5% rms gain uncertainty for GBT and OVRO measurements, respectively. Sources detected at greater than 4 sigma at 31 GHz are flagged (detection_flag = 'Y'); for this calculation, the random gain uncertainty was excluded. In all 3165 sources were observed. The GBT catalog (this table) contains 1490 sources. Of the 2315 useful OVRO observations many of the non-detections (and a few detections) were superceded by more sensitive GBT observations; the OVRO catalog contained in the HEASARC's OVRO31GHZ table therefore contains data on 1675 sources. The detection rate of the OVRO measurements was 11%, and that of the GBT measurements 25%. In all, 18% of the sources were detected at 31 GHz. This table was created by the HEASARC in June 2012 based on CDS Catalpog J/ApJ/704/1433 file table3.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/gwsstrpcxo
- Title:
- Groth-Westphal Strip Chandra X-Ray Point Source Catalog
- Short Name:
- GWSSTRPCXO
- Date:
- 18 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains the optical and X-ray spectral properties of the sources detected in a 200-ks Chandra observation of part of the Groth-Westphal Strip (GWS) region, using the ACIS-I instrument. The authors present a relatively simple method for the detection of X-ray point sources and the calculation of limiting sensitivities, which they argue is at least as sensitive and more self-consistent than previous methods presented in the literature. A total of 158 distinct X-ray sources are included in this point-source catalogue in the ACIS-I area with a threshold Poisson detection probability of 4 x 10<sup>-6</sup>. The number counts show a relative dearth of X-ray sources in this region. A wealth of optical photometric and spectroscopic data are available in this field providing optical identifications and redshift determinations for the X-ray population. The optical photometry and spectroscopy used here are primarily from the Deep Extragalactic Evolutionary Probe 2 (DEEP2) survey with additional redshifts obtained from the literature. These are complemented with the deeper (r ~ 26 mag) multiwaveband data (ugriz) from the Canada-France-Hawaii Telescope Legacy Survey to estimate photometric redshifts and to optically identify sources fainter than the DEEP2 magnitude limit (R<sub>AB</sub> ~ 24.5 mag). The authors focus their study on the 2 - 10 keV selected sample comprising 97 sources to the flux limit ~8 x 10<sup>-16</sup> erg/s/cm<sup>2</sup>, this being the most complete in terms of optical identification rate (86 per cent) and redshift determination fraction (63 per cent; both spectroscopic and photometric). Chandra observed the GWS, which is part of the Extended Groth Strip (EGS) region, on three separate occasions between 2002 August 11 and 22, using ACIS-I as the prime instrument. The S2 and S3 chips of the ACIS-S array were also operating during the observation, but as these are far off-axis their data are not considered further. The sequence number identifying the observations was 900144 and the three observation ID numbers (3305 on 2002-08-11, 4357 on 2002-08-12, and 4365 on 2002-08-21). This table was created by the HEASARC in July 2007 based on the merger of <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/MNRAS/356/568">CDS Catalog J/MNRAS/356/568</a> file table3.dat and <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/MNRAS/371/221">CDS Catalog J/MNRAS/371/221</a> file table2.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/hrasscat
- Title:
- Hamburg/RASS Catalog: X-Ray Sources
- Short Name:
- RASS/HRC
- Date:
- 18 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table is a representation of part of the Hamburg/ROSAT All-Sky Survey (RASS) Catalog (HRC) of optical identifications of X-ray sources at high-galactic latitude, namely the list of X-ray sources. (The list of proposed and possible optical counterparts is given in the linked Browse table HRASSOPTID). The HRC includes all X-ray sources from the ROSAT Bright Source Catalog (RASS-BSC) with galactic latitude |b| >= 30 degrees and declination Dec >= 0 degrees. In this part of the sky covering ~10,000 square degrees, the RASS-BSC contains 5341 X-ray sources. For the optical identification, the HRC authors used blue Schmidt prism and direct plates taken for the northern hemisphere Hamburg Quasar Survey (HQS) which are now available in digitized form. The limiting magnitudes are 18.5 and 20, respectively. For 82% of the selected RASS-BSC, an identification could be given. For the rest, either no counterpart was visible in the error circle, or a plausible identification was not possible. With ~42%, AGN represent the largest group of X-ray emitters, ~31% have a stellar counterpart, whereas galaxies and cluster of galaxies comprise only ~4% and ~5%, respectively. In ~3% of the RASS-BSC sources, no object was visible on the blue direct plates within 40" around the X-ray source position. The catalog has been used as a source for the selection of (nearly) complete samples of the various classes of X-ray emitters. This table was produced by the HEASARC in February 2005 based on the CDS Catalog table J/A+A/406/353/x-ray.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/a4
- Title:
- HEAO 1 A4 Catalog of High-Energy X-Ray Sources
- Short Name:
- A4
- Date:
- 18 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The HEAO 1 A-4 Catalog of High-Energy X-ray Sources represents results from an all-sky survey carried out at high X-ray energies (13-180 keV) from August 1977 until January 1979 using data obtained with the UCSD/MIT Hard X-Ray and Low-Energy Gamma-Ray Instrument on the HEAO 1 satellite. Quantitative results from a model-dependent fitting procedure are given in the form of fitted count rates in four broad energy bands for about 70 sources. The survey is complete, except in regions of source confusion, down to an intensity level of about 1/75 of the Crab Nebula in the 13-80 keV energy band. Forty-four sources were detected in the 40-80 keV energy band, and 14 in the 80-180 keV band. Most of the sources are galactic; seven are extragalactic. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/a2led
- Title:
- HEAO 1 A2 LED Catalog
- Short Name:
- A2LED
- Date:
- 18 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The HEAO 1 A-2 LED Catalog of High-Energy X-ray Sources is the result of a study of the diffuse X-ray sky over the bands of X-ray energies 0.18-0.44 keV and 0.44-2.8 keV from August 1977 until January 1979 using data obtained with the A-2 Low Energy Detector on the HEAO 1 satellite. The HEAO A-2 Experiment was primarily designed for studying the diffuse X-ray background; however, it was also capable of studying point sources to good sensitivity. The detectors surveyed over 95 percent of the sky in the spectral bands listed above to typical limiting sensitivities of 1x10**-11 and 3x10**-11 respectively. Using a significance criterion of 6 sigma for existence, 114 sources are cataloged. The catalog contains a list of all counterpart identifications and a cross-reference to all HEAO 1 A-2 LED team publications on the catalog sources complete through the end of 1981. The identified sources fall into several categories, primarily dependent on observing energy interval. In the 1 KeV band the sources include: 20 galactic stellar sources, 19 extragalactic sources, 13 SNR's, 11 galactic bulge sources, 2 globular cluster sources, and 2 previously reported sources without optical counterparts. In the .25 KeV band the sources include: 24 galactic stellar objects, 12 extragalactic sources, 5 SNR's, 1 bulge source, and 1 globular cluster source. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/a1
- Title:
- HEAO 1 A1 X-Ray Source Catalog
- Short Name:
- A1
- Date:
- 18 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The HEAO 1 A-1 X-Ray Source Catalog contains information about X-ray sources detected with the NRL Large Area Sky Survey Experiment (also referred to as the A-1 Experiment) flown aboard the HEAO-1 satellite. The catalog represents results from the first six months of data from HEAO-1, during which time a scan of the entire sky was completed. Positions and intensities for 842 sources are listed, with a limiting flux of 250 nanoJanskies (nJy) at 5 keV, or about 0.25 Uhuru flux units (UFU). The catalog is more than 90% complete at a flux level equivalent to 1.5 microJanskies (µJy) at 5 keV, for a Crab-like spectrum. The A-1 catalog has been cross-referenced with published literature. Identifications based on coincidence in position have been proposed for some of the sources for which previous work has established no firm identification. Half of the sources remained unidentified at the time of catalog publication (1984). The A3 database contains a list of 654 optical objects identified with A-1 error boxes. Minor structural changes were made to this database table and the documentation was revised by the HEASARC in July 2004. The basic content of the database table was unchanged, however. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/herschllog
- Title:
- Herschel Space Observatory Log of Observations
- Short Name:
- HERSCHLLOG
- Date:
- 18 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Herschel Space Observatory (Herschel) is an ESA (European Space Agency) project with instruments funded by ESA member states. It was operated from May 2009 till April 2013, offering unprecedented observational capabilities in the far-infrared and sub-millimeter spectral range (55-671 microns [um]). Herschel carried a 3.5m diameter passively cooled Cassegrain telescope, which was the largest of its kind and utilizes a novel silicon carbide technology. The science payload comprised three instruments: two direct detection cameras/medium resolution spectrometers, the Photodetector Array Camera and Spectrometer (PACS) and the Spectral and Photometric Imaging Receiver (SPIRE), and a very high-resolution heterodyne spectrometer, the Heterodyne Instrument for the Far Infrared or HIFI, whose focal plane units were housed inside a superfluid helium cryostat. PACS comprised two mutually exclusive sub-instruments: a bolometric camera designed to perform photometry in three spectral bands (70, 100 and 160 um) and an integral field unit grating spectrometer operating over the spectral range from 57 to 210 um with a spectral resolution ranging from 1000 to 5000. SPIRE comprised a three-band photometer, operating in spectral bands centered on 250, 350 and 500 um, and an imaging Fourier-Transform Spectrometer (FTS), which provided low resolution spectra over the 195-670 um band. Both instruments used germanium bolometers operating at 0.3 K and coupled to the telescope with hexagonally conical feedhorns. The photometer and the spectrometer were not designed to operate simultaneously. HIFI was designed to obtain spectra with very high resolution (up to 10<sup>7</sup>) in the far-infrared and sub-millimeter wavelengths not directly observable by ground-based telescopes. The HIFI instrument was an heterodyne receiver which provided spectroscopy in the continuous frequency range 480-1250 GHz (240-625 microns) and in the frequency range 1410-1910 GHz (157-213 microns). Herschel had two Announcement of Opportunities (AOs) for Open Time (OT) observations. The first in-flight AO for Open Time (OT1) was opened on 20 May 2010, with a deadline of 22 July 2010. For OT1, 241 observing programs were accepted and the total allocated observing time amounts to 6576.9 hours. The second in-flight AO for Open Time (OT2) was opened on 9 June 2011, with a deadline of 15 September 2011. There were parallel AOs for Guaranteed Time observations, GT1 and GT2, with separate deadlines. The Announcement of Opportunity (AO) for Herschel Key Programs (KP) was issued on 1 February 2007, with separate deadlines for guaranteed time (GT) and open time (OT) proposals. The whole Key Program AO process has now been completed, and by coincidence there were exactly the same number of KP GT and OT programs, in both cases 21 programs were awarded observing time. Taken together, these 42 observing programs contained 11,650 astronomical observation requests or AORs (AORs are the primary units of Herschel observing time and are effectively the Herschel 'observation units'). The total allocated observing time for these programs was 11,257.7 hours, corresponding to approximately 57% of the nominally available Herschel routine mission science time. Herschel successfully made over 37,000 scientific observations before its helium cryogen was exhausted. The HSA is available at the Herschel Science Centre at <a href="http://herschel.esac.esa.int/Science_Archive.shtml">http://herschel.esac.esa.int/Science_Archive.shtml</a>, the Herschel help desk is at <a href="http://herschel.esac.esa.int/esupport/">http://herschel.esac.esa.int/esupport/</a>, the Herschel User Provided Data Products are available at <a href="http://herschel.esac.esa.int/UserProvidedDataProducts.shtml">http://herschel.esac.esa.int/UserProvidedDataProducts.shtml</a>, the Herschel Postcard Server is at <a href="http://archives.esac.esa.int/hsa/aio/doc/postcardGallery.html">http://archives.esac.esa.int/hsa/aio/doc/postcardGallery.html</a>, and the Herschel Observation Log is at<a href="http://herschel.esac.esa.int/logrepgen/observationlist.do">http://herschel.esac.esa.int/logrepgen/observationlist.do</a> This table was created by the HEASARC in October 2013 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/VI/139">CDS Catalog VI/139</a> file herschel.dat. This is a service provided by NASA HEASARC .
