- ID:
- ivo://nasa.heasarc/rcw49cxo
- Title:
- RCW 49 Chandra X-Ray Point Source Catalog
- Short Name:
- RCW49CXO
- Date:
- 25 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains the list of X-ray sources detected in a high-resolution X-ray imaging study of the stellar population in the Galactic massive star-forming region RCW 49 and its central OB association Westerlund 2. The authors obtained a ~ 40 ks X-ray image of a ~ 17' x 17' field using the Chandra X-Ray Observatory and deep NIR images using the Infrared Survey Facility in a concentric ~ 8.3' x 8.3' region. They detected 468 X-ray sources with a photometric significance >=1.0 and a 1% or less chance of being a background fluctuation, and identified optical, near-infrared (NIR), and Spitzer mid-infrared (MIR) counterparts for 379 of them. The unprecedented spatial resolution and sensitivity of the X-ray image, enhanced by optical and infrared imaging data, yielded the following results: (1) The central OB association Westerlund 2 is resolved for the first time in the X-ray band. X-ray emission is detected from all spectroscopically identified early-type stars in this region. (2) Most (~ 86%) X-ray sources with optical or infrared identifications are cluster members in comparison with a control field in the Galactic plane. (3) A loose constraint (2-5 kpc) for the distance to RCW 49 is derived from the mean X-ray luminosity of T Tauri stars. (4) The cluster X-ray population consists of low-mass pre-main-sequence and early-type stars as obtained from X-ray and NIR photometry. About 30 new OB star candidates are identified. (5) The authors estimate a cluster radius of 6' - 7' based on the X-ray surface number density profiles. (6) A large fraction (~ 90%) of cluster members are identified individually using complimentary X-ray and MIR excess emission. (7) The brightest five X-ray sources, two Wolf-Rayet stars and three O stars, have hard thermal spectra. The X-ray observation of RCW 49 was carried out using the Advanced CCD Imaging Spectrometer (ACIS) on board the Chandra X-Ray Observatory from 2003 August 23 UT 18:20 to August 24 UT 4:54. Four imaging array (ACIS-I) chips covered a 17 by 17 arcminutes field centered at (R.A., Dec.) = (10h24m00.5s, -57d 45' 18") in the equinox J2000.0 for a 36.7 ks exposure. ACIS-I covers the 0.5 - 8.0 keV energy band with a spectral resolution of ~ 150 eV at 6 keV and a point-spread function (PSF) radius of ~ 0.5" within ~ 2' of the on-axis position, degrading to ~ 6" at a 10' off-axis angle. The data were taken with the very faint telemetry mode and the timed exposure CCD operation with a frame time of 3.2 s. Sources with photometric significance of larger than 2 were fitted with an absorbed thin thermal plasma model. The abundance was fixed to be 0.3 times the solar value. Fits lacking uncertainties, fits with large uncertainties, and fits with frozen parameters should be viewed merely as splines to the data to obtain rough estimates of the X-ray luminosities: the listed parameter values are considered unreliable in such cases. The authors also conducted NIR observations on 2004 December 25 and 28 using the Simultaneous three-color Infrared Imager for Unbiased Surveys (SIRIUS) mounted on the Cassegrain focus of the IRSF 1.4 m telescope at the South African Astronomical Observatory. SIRIUS is a NIR imager capable of obtaining simultaneous images in the J, H, and K<sub>s</sub> bands. The instrument is equipped with three HAWAII arrays of 1024 by 1024 pixels. The pixel scale of 0.45" is an excellent match with the on-axis spatial resolution of Chandra. The authors covered 8.3 by 8.3 arcminute fields at two positions, one aimed at RCW 49 (10h24m01.9s, -57d 45' 31") and the other at a control region. This table was created by the HEASARC in October 2007 based on the versions of Tables 1, 2, and 3 from the paper which were obtained from the electronic ApJ website. This is a service provided by NASA HEASARC .
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- ID:
- ivo://nasa.heasarc/rcw108cxo
- Title:
- RCW 108 Star Formation Region Chandra X-Ray Point Source Catalog
- Short Name:
- RCW108CXO
- Date:
- 25 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains some of the results of an approximately 90 ks Chandra observation of a complex region that hosts multiple sites of recent and active star formation in ARA OB1a. The field is centered on the embedded cluster RCW 108-IR and includes a large portion of the open cluster NGC 6193. The authors detected over 420 X-ray sources in the field and combined these data with deep near-IR, Spitzer/IRAC and Midcourse Space Experiment (MSX) mid-IR data. They find that about 360 of the X-ray sources have near-IR counterparts. They divide the region into five parts based on the X-ray point source characteristics and extended 8 micron emission. The most clearly defined regions are the central region, identified by embedded sources with high luminosities in the both the near-IR and X-ray as well as high X-ray temperatures (~3 keV), and the eastern region, identified by low extinction and ~1 keV X-ray temperatures. Other regions, identified by their directional relationship to RCW 108-IR, are less uniform, representing combinations of the first two regions, independent star formation epochs, or both. The cluster members range in X-ray luminosity from 10<sup>29</sup> to 10<sup>33</sup> erg s<sup>-1</sup>. Over 18% of the cluster members with over 100 counts exhibit flares. All sources with over 350 counts are variable. Overall about 10% (16% in RCW 108-IR) appear to have optically thick disks as derived from their position in the (J - H), (H - K) diagram. The disk fraction becomes much higher when IRAC data are employed. The largest fraction of X-ray sources is best described as possessing some disk material via a more detailed extinction fitting. The authors fit the bulk of the X-ray spectra as absorbed Raymond-Smith-type plasmas, and find that the column to the RCW 108-IR members varies from 10<sup>21</sup> to 10<sup>23</sup> cm<sup>-2</sup>. They find that the field contains 41 candidate O or B stars, and estimate that the total number of pre-main-sequence stars in the field is about 1600 +/- 200. Approximately 800 are confined to the 3' (~1.1 pc) central region. The field was observed by Chandra on 2004 October 25 starting at 02:37 UT for 92.2 ks of total time and 88.8 ks of so-called "good-time" (ObsId 4503). The ACIS was used in the nominal imaging array (chips I0-I3) which provides a field of view of approximately 17' by 17' (~6.5 pc on a side). The aimpoint was at RA, Dec = 16:39:58.7, -48:51:54.4 (J2000.0). In addition, the S2 and S3 chips were on and located over IRAS 16379-4856. About 20 point sources were detected associated with this object; however, the analysis of these data is not presented here because they are far off-axis. This table was created by the HEASARC in June 2008 based on electronic versions of Tables 1, 2, 5, 7, 10 and 11 from the reference paper which were obtained from the Astronomical Journal web site. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/rcw38yso
- Title:
- RCW 38 Young Stellar Objects Catalog
- Short Name:
- RCW38YSO
- Date:
- 25 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains some of the results from a study of the structure of the high-mass star-forming region RCW 38 and the spatial distribution of its young stellar population. Spitzer Infrared Array Camera (IRAC) photometry (3-8 micron) is combined with Two Micron All Sky Survey (2MASS) near-IR data to identify young stellar objects (YSOs) by IR-excess emission from their circumstellar material. Chandra X-ray data are used to identify class III pre-main-sequence stars lacking circumstellar material. The authors identify 624 YSOs: 23 class 0/I and 90 flat spectrum (FS) protostars, 437 class II stars, and 74 class III stars. They also identify 29 (27 new) O star candidates over the IRAC field. Seventy-two stars exhibit IR-variability, including 7 class 0/I and 12 flat spectrum YSOs. A further 177 tentative candidates are identified by their location in the IRAC [3.6] versus [3.6]-[5.8] color-magnitude diagram. The authors find strong evidence of subclustering in the region. Three subclusters were identified surrounding the central cluster, with massive and variable stars in each subcluster. The central region shows evidence of distinct spatial distributions of the protostars and pre-main-sequence stars. A previously detected IR cluster, DB2001_Obj36, has been established as a subcluster of RCW 38. This suggests that star formation in RCW 38 occurs over a more extended area than previously thought. The gas-to-dust ratio is examined using the X-ray derived hydrogen column density, NH and the K-band extinction, and found to be consistent with the diffuse interstellar medium, in contrast with Serpens and NGC 1333. The authors posit that the high photoionizing flux of massive stars in RCW 38 affects the agglomeration of the dust grains. This table contains the list of 624 young stellar objects (given in Tables 3 and 4 of the reference paper) found among the Spitzer sources in the field of RCW 38 using the two selection techniques described in Section 3 of the reference paper: (1) selection of stars with IR excesses in IR color-color diagrams, and (2) identification of X-ray luminous YSOs by comparing X-ray sources with IR detections. The latter technique was used to identify Type III YSOs lacking emission from a dusty disk. This table does NOT contain (i) the 177 candidate YSOs listed in Table 5 of the reference paper which were identified using the [3.6] versus [3.6] - [5.8] color-magnitude diagram, since contamination removal methods could not be utilized for these objects, (ii) the 24 candidate variable YSOs listed in Table 6 of the reference paper, nor (iii) 21 of the 29 candidate O-star cluster members which were listed in table 7 of the reference paper. This table was created by the HEASARC in January 2012 based on an electronic version of Tables 3 and 4 from the reference paper which were obtained from the ApJ web site. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/ariel3a
- Title:
- 3rd Ariel-V SSI Catalog
- Short Name:
- ARIEL3A
- Date:
- 25 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The 3rd Ariel-V SSI Catalog contains a list of X-ray sources detected by the University of Leicester's Sky Survey Instrument (SSI) on the Ariel-V satellite, and published (in 2 papers) as the Ariel-V (3A) Catalog: Warwick et al. 1981, MNRAS, 197, 865 (the low galactic latitude sources) and McHardy et al. 1981, MNRAS, 197, 893 (the high galactic latitude sources). The catalog is based on observations extending over a 5.5 year period from 1974 October until 1980 March. The SSI had a field of view of 0.75 by 10.6 degrees (FWHM) and had an energy range from 2 to 18 keV. A detailed description of the SSI is given by Villa et al. 1976, MNRAS, 176, 609. For a more detailed discussion of how the 3A Catalog was created, please refer to the Warwick et al. (1981) and McHardy et al. (1981) papers. This online catalog was created by the HEASARC in March 2003 based on the merger of two original tables originally obtained from the ADC website (<a href="https://heasarc.gsfc.nasa.gov/FTP/heasarc/dbase/misc_files/ariel3a/hilat.dat">https://heasarc.gsfc.nasa.gov/FTP/heasarc/dbase/misc_files/ariel3a/hilat.dat</a> and <a href="https://heasarc.gsfc.nasa.gov/FTP/heasarc/dbase/misc_files/ariel3a/lowlat.dat">https://heasarc.gsfc.nasa.gov/FTP/heasarc/dbase/misc_files/ariel3a/lowlat.dat</a>). This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/revisedlhs
- Title:
- Revised Luyten Half-Second (LHS) Catalog
- Short Name:
- LuytenHS
- Date:
- 25 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Revised Luyten Half-Second (LHS) Catalog contains refined coordinates and proper motion data for the high proper motion (HPM) stars listed in the Original Luyten Half-Second (LHS) catalog. The positional uncertainty in the Original LHS catalog is typically >10" and is often >30". The authors of the Revised LHS Catalog used the digital scans of the Palomar Observatory Sky Survey (POSS) I and POSS II plates to derive more accurate positions and proper motions for these objects. Out of the 4470 candidates in the LHS catalog, 4323 objects were manually re-identified in the POSS I and POSS II scans. A small fraction of the stars were not found due to the lack of finder charts and digitized POSS II scans. The uncertainties in the revised positions are typically ~2", but can be as high as ~8" in a few cases, which is a large improvement over the original data. Cross-correlation with the Tycho-2 and Hipparcos catalogs yielded 819 candidates (with red magnitude m_R <~12. For these brighter sources, the position and proper motion data were replaced with the more accurate Tycho/Hipparcos data. In total, there are revised proper motion measurements and coordinates for 4040 stars and revised coordinates for 4330 stars. This table was created by the HEASARC in October 2002 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/I/279">CDS Catalog I/279</a> (the 24-May-2002 version of the file catalog.dat). This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/rhoophcxo
- Title:
- Rho Ophiuchi SFR Chandra X-Ray Point Source Catalog
- Short Name:
- RHOOPHCXO
- Date:
- 25 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This catalog of X-ray sources represents some of the results of a systematic study of X-ray flares from low-mass young stellar objects, using two deep exposure Chandra observations of the main region of the rho Ophiuchi star-forming cloud. From 195 X-ray sources, including class I-III pre-main sequence sources and some young brown dwarfs, a total of 71 X-ray flares were detected. The Chandra X-ray Observatory (Weisskopf et al., 2002PASP..114....1W) observed the central region of rho Oph twice with a deep exposure of the ACIS-I array, consisting of four abutted X-ray CCDs. The first observation (here and after, obs. BF) covered the south-east 17.4' x 17.4' area, including cores B, C, E, and F, while the second observation (obs. A) covered the north-west area centered on core A (Loren et al., 1990ApJ...365..269L). This table contains data and the results of spectral and timing analyses on the 195 sources detected in the two rho Oph fields, 9 of which were detected in both fields and are therefore listed twice (A-61=BF-2, A-64=BF-4, A-65=BF-5, A-69=BF-7, A-75=BF-11, A-77=BF-15, A-78=BF-16, A-79=BF-17, and A-81 = BF-19). Sources which flared have multiple entries, with one entry (typically, but not always) listing the properties of the quiescent emission, and additional entries for individual flares which were analyzed separately. For the very faint sources for which the temperatures obtained from X-ray spectral analyses were not constrained, there are typically two entries in this table per source, one of which gives the results of a spectral analysis in which the temperature was fixed at 1 keV (11.6 MK) and the other in which the temperature was instead fixed at 5 keV (58 MK). Thus, there are more entries (306) in this HEASARC table than the number (195) of detected rho Oph X-ray sources. This table was created by the HEASARC in February 2007 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/PASJ/55/653">CDS Catalog J/PASJ/55/653</a> files table2.dat and table3.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/ritterrbin
- Title:
- Ritter Binaries Related to CVs Catalog (7.21 Edition)
- Short Name:
- Ritter/Bin
- Date:
- 25 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This HEASARC database table contains information on the so-called "Related Objects" only, as taken from the Catalog of Cataclysmic Binaries, Low-Mass X-ray Binaries, and Related Objects (7th Edition, Release 7.21, March 2014) of Ritter & Kolb. The complete catalog lists coordinates, apparent magnitudes, orbital parameters, stellar parameters of the components, and other characteristic properties of 1166 cataclysmic binaries, 105 low-mass X-ray binaries, and 500 related objects with known or suspected orbital periods. The HEASARC has for simplicity split this catalog into three Browse database tables, one for each class of objects: the present table (RITTERRBIN) containing the related binaries' data, a second one (<a href="/W3Browse/star-catalog/rittercv.html">RITTERCV</a>) containing cataclysmic binaries' data, and a third one (<a href="/W3Browse/star-catalog/ritterlmxb.html">RITTERLMXB</a>) containing the low-mass X-ray binaries' data. The literature published before 1 January 2014 has, as far as possible, been taken into account. Related objects are detached binaries consisting of either a white dwarf or a white dwarf precursor primary and of a low-mass secondary. The secondary may also be a highly evolved star. This table was last updated by the HEASARC in April 2014 based on the pcbdata.dat file from the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/B/cb">CDS Catalog B/cb</a>. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/rittercv
- Title:
- Ritter Cataclysmic Binaries Catalog (7.21 Edition)
- Short Name:
- Ritter/CV
- Date:
- 25 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This HEASARC database table contains information on cataclysmic binaries only, as taken from the Catalog of Cataclysmic Binaries, Low-Mass X-ray Binaries, and Related Objects (7th Edition, Release 7.21, March 2014) of Ritter & Kolb. The complete catalog lists coordinates, apparent magnitudes, orbital parameters, stellar parameters of the components, and other characteristic properties of 1166 cataclysmic binaries, 105 low-mass X-ray binaries, and 500 related objects with known or suspected orbital periods. The HEASARC has for simplicity split this catalog into three Browse database tables, one for each class of objects: the present table (RITTERCV) containing the cataclysmic binaries' data, a second one (<a href="/W3Browse/star-catalog/ritterlmxb.html">RITTERLMXB</a>) containing the low-mass X-ray binaries' data, and a third one (<a href="/W3Browse/star-catalog/ritterrbin.html">RITTERRBIN</a>) containing the related binaries' data. The literature published before 1 January 2014 has, as far as possible, been taken into account. Cataclysmic binaries are semi-detached binaries consisting of a white dwarf (or a white dwarf precursor) primary and a low-mass secondary which is filling its critical Roche lobe. The secondary is not necessarily unevolved, it may even be a highly evolved star, as, for example, in the case of the AM CVn-type stars. This table was last updated by the HEASARC in April 2014 based on the cbdata.dat file from the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/B/cb">CDS Catalog B/cb</a>. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/ritterlmxb
- Title:
- Ritter Low-Mass X-Ray Binaries Catalog (7.21 Edition)
- Short Name:
- Ritter/LMXB
- Date:
- 25 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This HEASARC database table contains information on low-mass X-ray binaries (LMXBs) only, as taken from the Catalog of Cataclysmic Binaries, Low-Mass X-ray Binaries, and Related Objects (7th Edition, Release 7.21, March 2014) of Ritter & Kolb. The complete catalog lists coordinates, apparent magnitudes, orbital parameters, stellar parameters of the components, and other characteristic properties of 1166 cataclysmic binaries, 105 low-mass X-ray binaries, and 500 related objects with known or suspected orbital periods. The HEASARC has for simplicity split this catalog into three Browse database tables, one for each class of objects: the present table (RITTERLMXB) containing the low-mass X-ray binaries' data, a second one (<a href="/W3Browse/star-catalog/rittercv.html">RITTERCV</a>) containing cataclysmic binaries' data, and a third one (<a href="/W3Browse/star-catalog/rittercv.html">RITTERRBIN</a>) containing the related binaries' data. The literature published before 1 January 2014 has, as far as possible, been taken into account. Low-mass X-ray binaries are semi-detached binaries consisting of either a neutron star or a black hole primary, and a low-mass secondary which is filling its critical Roche lobe. This table was last updated by the HEASARC in April 2014 based on the lmxbdata.dat file from the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/B/cb">CDS Catalog B/cb</a>. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/romabzcat
- Title:
- Roma-BZCAT Multi-Frequency Catalog of Blazars
- Short Name:
- ROMABZCAT
- Date:
- 25 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains the 5th edition of the Roma-BZCAT catalog of blazars which contains coordinates and multi-frequency data of 3561 sources. It presents several relevant changes with respect to the past editions which are briefly described in the reference paper. The Roma-BZCAT catalog contains data on 3561 sources, about 30% more than in the 1st edition, which either confirmed blazars or exhibiting characteristics close to this type of sources. With respect to the previous editions, this new edition has relevant changes in the sources' classification. The authors emphasize that all the sources in the Roma-BZCAT have a detection in the radio band. Moreover, complete spectroscopic information is published and could be accessed by the authors for all of them, with the exception of BL Lac candidates. Consequently, peculiar sources such as the so called "radio quiet BL Lacs", which are reported in some other catalogs, are not included here because of possible contamination by hot stars and other extragalactic objects. In the 5th edition, the authors use a similar denomination for the blazars to that adopted in the previous editions. Each blazar is identified by a code, with 5BZ for all blazars, a fourth letter that specifies the type (B, G, Q or U), followed by the truncated equatorial coordinates (J2000). The authors introduced the edition number before the letters BZ to avoid possible confusion due to the fact that several sources changed their old names because of a newly adopted classification. The 5th edition contains 1151 BZB sources (92 of which are reported as candidates because their optical spectra could not be found in the literature), 1909 BZQ sources, 274 BZG sources, and 227 BZU objects. This database table was originally ingested by the HEASARC in September 2013, based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/495/691">CDS Catalog J/A+A/495/691</a> file bzcat4.dat. It was updated in March 2016, and it is now based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/VII/274">CDS Catalog VII/274</a> file bzcat5.dat. This is a service provided by NASA HEASARC .
