Orion Nebula Cluster Chandra HRC X-Ray Point Source Catalog
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In the first of two companion papers on the Orion Nebula Cluster (ONC), the authors presented their analysis of a 63 ks Chandra HRC-I observation that yielded 742 X-ray detections within the 30' x 30' field of view. To facilitate their interpretation of the X-ray image, they compiled a multi-wavelength catalog of nearly 2900 known objects in the region by combining 17 different catalogs from the recent literature. They defined two reference groups: an infrared sample, containing all objects detected in the K band, and an optical sample comprising low-extinction, well-characterized ONC members. They showed for both samples that field object contamination is generally low. Their X-ray sources are primarily low-mass ONC members. The detection rate for optical sample stars increases monotonically with stellar mass from zero at the brown dwarf limit to ~100% for the most massive stars but shows a pronounced dip between 2 and 10 M
sun. They determined L
X and L
X/L
bol or all stars in their optical sample and utilized this information in their companion paper to study correlations between X-ray activity and other stellar parameters. In particular, the authors assembled an extensive catalog of known X-ray/optical/IR and radio objects that fell within the HRC FOV. In addition to their list of HRC sources and the Chandra source lists of Garmire et al. (2000,
CDS Cat. ) and Schulz et al. (2001, CDS Cat.
), they considered 14 catalogs from recent publications, producing a database of nearly 2900 distinct objects reported in at least one of the studies considered. A full list of references is given in the first column of Table 2 of the reference paper, along with a concise classification of the work and the referenced table number(s) from the original work. The HRC on board the Chandra X-Ray Observatory (Weisskopf et al., 2002PASP..114....1W) observed the ONC for 63.2ks on 2000 February 4. The pointing (R.A. = 5h 35m 17s, DE=-5{deg} 23' 16" (J2000.0)) was chosen to place the Trapezium region and the bright O star Theta1 Ori C in the center of the field of view (FOV). A good fraction of the ONC region was included in the 30' x 30' HRC FOV. This HEASARC table lists the properties of the 742 X-ray sources detected in this observation as presented in the full version of Table 1 of the reference paper. This table was created by the HEASARC in March 2007 based on the CDS table J/ApJ/582/382, file table1.dat. This is a service provided by NASA HEASARC .
VLA A2390 Cluster of Galaxies 1.4-GHz Source Catalog
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This table contains the 1.4-GHz source catalog for the field of the cluster of galaxies A2390 as observed with the Very Large Array (VLA). This is one of the deepest radio images of a cluster field ever taken. The image covers an area of 34' x 34' with a synthesized beam of ~1.4" and a noise level of ~5.6 µJy (µJy) near the field center. In the reference paper, the authors construct differential number counts for the central regions (radius < 16') of this cluster, and find that the faint (S
1.4GHz < 3 mJy) counts of A2390 are roughly consistent with the lowest blank field number counts. Their analyses indicate that the number counts are primarily from field radio galaxies. The authors suggest that the disagreement of their number counts for this cluster with those from a similarly deep observation of A370 that was also presented in the reference paper can be largely attributed to cosmic variance. The authors observed the A2390 cluster field with the VLA in the A configuration for ~31.4hr on-source during 2008 October. The field center is located at 21:53:36 +17:41:52 (J2000). This table was created by the HEASARC in August 2017 based on
CDS Catalog J/ApJS/202/2/ file table2.dat. This file contained 699 entries for sources detected at 1.4 GHz in the A370 field, as well as 524 entries for sources detected at 1.4 GHz in the A2390 field. Only the latter are included in this HEASARC table, while the former can be found in the HEASARC's
VLA3701P4 table. This is a service provided by NASA HEASARC .
VLA A370 Cluster of Galaxies 1.4-GHz Source Catalog
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This table contains the 1.4-GHz source catalog for the field of the cluster of galaxies A370 as observed with the Very Large Array (VLA). This is one of the deepest radio images of a cluster field ever taken. The image covers an area of 40' x 40' with a synthesized beam of ~1.7" and a noise level of ~5.7 µJy (µJy) near the field center. The authors have cataloged 200 redshifts for the A370 field. In the reference paper, they construct differential number counts for the central regions (radius < 16') of this cluster, and find that the faint (S
1.4GHz < 3 mJy) counts of A370 are roughly consistent with the highest blank field number counts. Their analyses indicate that the number counts are primarily from field radio galaxies. The authors suggest that the disagreement of their number counts for this cluster with those from a similarly deep observation of A2390 that was also presented in the reference paper can be largely attributed to cosmic variance. The authors observed the A370 cluster field with the VLA in the A configuration for ~42.4hr on-source during 1999 August and September. K. S. Dwarakanath observed A370 in the B configuration for ~18.4hr on-source during 1994 August and September. The field center is located at 02:39:32 -01:35:07 (J2000). This is offset by approximately 5 arcminutes from the cluster center at 02:39:50.5 -01:35:08. The authors also targeted 58 radio sources, in A370, that had no existing optical spectral data using the Hydra fiber spectrograph on the Wisconsin-Indiana-Yale-NOAO (WIYN) telescope (spectral window of ~4500 - 9500 Angstrom). They preferentially targeted optically bright galaxies, obtaining these data in a single two-hour pointing on 2012 January 20. Of the 58 targets, the authors obtained high-confidence redshifts for 36. This table was created by the HEASARC in August 2017 based on
CDS Catalog J/ApJS/202/2/ file table2.dat. This file contained 699 entries for sources detected at 1.4 GHz in the A370 field, as well as 524 entries for sources detected at 1.4 GHz in the A2390 field. Only the former are included in this HEASARC table, while the latter can be found in the HEASARC's
VLA23901P4 table. This is a service provided by NASA HEASARC .
Orion Nebula Cluster Chandra HRC Optical Sample
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In the first of two companion papers on the Orion Nebula Cluster (ONC), the authors presented their analysis of a 63 ks Chandra HRC-I observation that yielded 742 X-ray detections within the 30' x 30' field of view. To facilitate their interpretation of the X-ray image, they compiled a multi-wavelength catalog of nearly 2900 known objects in the region by combining 17 different catalogs from the recent literature. They defined two reference groups: an infrared sample, containing all objects detected in the K band, and an optical sample comprising low-extinction, well-characterized ONC members. They showed for both samples that field object contamination is generally low. Their X-ray sources are primarily low-mass ONC members. The detection rate for optical sample stars increases monotonically with stellar mass from zero at the brown dwarf limit to ~100% for the most massive stars but shows a pronounced dip between 2 and 10 M
sun. They determined L
X and L
X/L
bol or all stars in their optical sample and utilized this information in their companion paper to study correlations between X-ray activity and other stellar parameters. In particular, the authors assembled an extensive catalog of known X-ray/optical/IR and radio objects that fell within the HRC FOV. In addition to their list of HRC sources and the Chandra source lists of Garmire et al. (2000,
CDS Cat. ) and Schulz et al. (2001, CDS Cat.
), they considered 14 catalogs from recent publications, producing a database of nearly 2900 distinct objects reported in at least one of the studies considered. A full list of references is given in the first column of Table 2 of the reference paper, along with a concise classification of the work and the referenced table number(s) from the original work. The authors' ONC optical sample is comprised of stars in the HRC FOV for which they have a mass estimate, whose values of the visual absorption AV are less than 3.0, and which are either confirmed proper motion members or have unknown proper motion (see Section 3.4.1 of the reference paper). For the 696 stars of this optical sample, this HEASARC table (the full version of Table 4 of the reference paper) lists sky position, mass, age, rotational period, Ca II line equivalent width, HRC basal count rate (see Section 5 of the reference paper), X-ray luminosity, and LX/Lbol (see Sections 4 and 5 of the reference paper). This table was created by the HEASARC in March 2007 based on the CDS table J/ApJ/582/382, file table4.dat. This is a service provided by NASA HEASARC .
VLA Goulds Belt Survey Orion Complex Source Catalog
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This table contains results from a high-sensitivity (60 µJy), large-scale (2.26 deg2) survey obtained with the Karl G. Jansky Very Large Array (JVLA) as part of the Gould's Belt Survey (GBS) program. The authors detected 374 and 354 sources at 4.5 and 7.5 GHz, respectively. Of these, 148 are associated with previously known young stellar objects (YSOs). Another 86 sources previously unclassified at either optical or infrared wavelengths exhibit radio properties that are consistent with those of young stars. The overall properties of these sources at radio wavelengths such as their variability and radio to X-ray luminosity relation are consistent with previous results from the GBS. These detections provide target lists for follow-up Very Long Baseline Array radio observations to determine their distances, as YSOs are located in regions of high nebulosity and extinction, making it difficult to measure their optical parallaxes. The observations were obtained with the JVLA of the National Radio Astronomy Observatory (NRAO) in its A configuration. The observations of the 210 fields in the Orion Molecular Clouds A and B were obtained in three different epochs (2011 June 25 to July 4, July 23 to 30, and August 25 to 29, as described in Table 1 of the reference paper) typically separated from one another by a month. The 210 individual fields have been split into 7 maps, with 30 fields being observed per map, as follows: 12 in the lambda Ori region, 3 in L1622, 27 are shared between NGC 2068 and NGC 2071, 14 are shared between NGC 2023 and NGC 2024, 11 in the sigma Ori region, 109 in the Orion Nebula Cluster (ONC), 16 in L1641-N, 8 in L1641-C, and 10 in L1641-S (see Figures 1 to 7 in the reference paper). Two frequency sub-bands, each 1-GHz wide, and centered at 4.5 and 7.5 GHz, respectively, were recorded simultaneously. The authors achieved a nearly uniform rms noise of 60 µJy beam-1 at both frequencies in all the regions. The only exception to this is in the Trapezium region due to nebular emission; there the noise was 200 µJy beam-1 after excluding baselines smaller than 150 kilo-lambda during imaging to remove extended emission. Sources were identified through a visual inspection of the individual fields at 4.5 GHz during the cleaning and imaging process since an automated source identification was deemed to be not sufficiently advanced and produced results that were too unreliable. In particularly clustered regions such as the Trapezium and NGC 2024, in addition to standard imaging, data from all three epochs were combined into a single image for source identification purposes only to improve statistical significance of each detection. The authors detected a combined total of 374 sources among the three epochs for all of the regions. All sources but one had fluxes greater than five times the rms noise in at least one epoch. The remaining source, 'GBS-VLA J053518.67-052033.1', was detected at two epochs with maximum detection probability of 4.9 sigma in a single epoch data. It is found in the Trapezium region, and has known counterparts in other wavelength regimes. The authors cross-referenced their catalog of sources with previous major radio, infrared, optical and X-ray surveys of the regions published in the literature. They have generally considered sources in these surveys to be counterparts if they had positional coincidences less than 1 arcsecond, but have allowed for larger offsets if the combined uncertainty between the databases was large. Of 374 detected sources, 261 have been previously found at another wavelength region, while 113 are new detections. 146 sources have been detected in X-rays, 94 at optical wavelengths, 218 at infrared, and 63 in previous radio surveys. Of the previously identified sources, 1 is extragalactic, while the other 148 as young stellar objects (YSOs). Of the YSOs, 106 have been placed on the standard class system based on the IRAC color-color classification of
Orion Flanking Fields Chandra X-Ray Point Source Catalog
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This table contains the results of Chandra observations of two flanking fields (FFs) in Orion outside the Orion Nebula Cluster (ONC), in the form of a catalog of 417 sources, which includes X-ray luminosity, optical and infrared photometry, and X-ray variability information. 91 variable sources were found, 33 of which have flarelike light curves, and 11 of which have a pattern of a steady increase or decrease over a 10 hour period. The optical and infrared photometry for the stars identified as X-ray sources are consistent with most of these objects being pre-main-sequence stars with ages younger than 10 Myr. The two flanking fields in Orion were observed with the Advanced CCD Imaging Spectrometer (ACIS) detector on board the Chandra X-Ray Observatory. The north Orion flanking field (NOFF) is centered at a J2000 RA and Declination of 05:35:19, -04:48:15, which is about 36' (~5 pc, at a distance of 470 pc) north of the Trapezium cluster and was observed on 2002 August 26 with a total exposure time of 48.8 ks. The south Orion flanking field (SOFF), centered at a J2000 RA and Declination of 05:35:06, -05:40:48, which is about 17' (~ 2.5pc, at a distance of 470 pc) south of the Trapezium cluster, was observed on 2002 September 6 with a total exposure time of 47.9 ks. The data analysis for these observations was performed in the same manner as described in Ramirez et al. (2004, AJ, 127, 2659) for a similar observation of a field in NGC 2264, which should be consulted for the full details. (See also the help file for the HEASARC version of the catalog from the latter reference available at /W3Browse/chandra/ngc2264cxo.html ). This table was created by the HEASARC in February 2007 based on the CDS table J/AJ/128/787, files table1.dat, table3.dat and table4.dat. It does not include the results from the spectral analysis of 44 bright X-ray sources which were presented in Table 2 of the reference paper. This is a service provided by NASA HEASARC .
NGC 4649 Chandra X-Ray Point Source Catalog 2
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This table contains the main X-ray source catalog for the Chandra monitoring observations of the 16.5-Mpc distant elliptical galaxy, NGC 4649. The galaxy has been observed with Chandra ACIS-S3 in six separate pointings, reaching a total exposure of 299 ks. There are 501 X-ray sources detected in the 0.3-8.0 keV band in the merged observation or in one of the six individual observations; 399 sources are located within the D25 ellipse. The observed 0.3-8.0 keV luminosities of these 501 sources range from 9.3 x 1036 erg s-1 to 5.4 x 1039 erg s-1. The 90% detection completeness limit within the D25 ellipse is 5.5 x 1037 erg s-1. Based on the surface density of background active galactic nuclei (AGNs) and the detection completeness, we expect ~ 45 background AGNs among the catalog sources (~ 15 within the D25 ellipse). There are nine sources with luminosities greater than 1039 erg s-1, which are candidates for ultraluminous X-ray sources. The nuclear source of NGC 4649 is a low-luminosity AGN, with an intrinsic 2.0-8.0 keV X-ray luminosity of 1.5 x 1038 erg s-1. The X-ray colors suggest that the majority of the catalog sources are low-mass X-ray binaries (LMXBs). The authors find that 164 of the 501 X-ray sources show long-term variability, indicating that they are accreting compact objects, and discover four transient candidates and another four potential transients. They also identify 173 X-ray sources (141 within the D25 ellipse) that are associated with globular clusters (GCs) based on Hubble Space Telescope and ground-based data; these LMXBs tend to be hosted by red GCs. Although NGC 4649 has a much larger population of X-ray sources than the structurally similar early-type galaxies, NGC 3379 and NGC 4278, the X-ray source properties are comparable in all three systems. This HEASARC table contains the main Chandra source catalog of the basic properties of the 501 X-ray detected sources (Table 3 in the reference paper which includes both sources detected in the merged X-ray image as well as a number only detected in the individual observations), and also the information on source counts, hardness ratios and soft and hard X-ray colors in the merged observation for the same 501 X-ray detected sources (Table 4 in the reference paper). It does not contain the information on source counts, hardness ratios and soft and hard X-ray colors for these same sources in the six individual observations that were contained in Tables 5 - 10 of the reference paper. This table was created by the HEASARC in March 2013 based on the electronic version of Tables 3 and 4 from the reference paper which were obtained from the ApJS website.. This is a service provided by NASA HEASARC .
NGC 6530 Chandra Point Source Optical/IR Identifications Catalog
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The authors have obtained astrometry and BVI photometry, down to a V magnitude of ~22, of the very young open cluster NGC 6530, from observations taken with the Wide Field Imager (WFI) camera at the MPG/ESO 2.2m Telescope. They have positionally matched their optical catalog with the list of X-ray sources found in a Chandra-ACIS observation of this cluster (Damiani et al. 2004, ApJ, 608, 781: available in Browse both via links from this table and also as the NGC6530CXO table), finding a total of 828 stars in common, 90% of which are pre-main sequence stars in NGC 6530. The data used in this work come from the combination of optical BVI images taken with the WFI camera made on 27-28 July 2000, a 60 ks Chandra ACIS X-ray observation, and public near-infrared data from the All-Sky Catalog of Point Sources of the Two Micron All Sky Survey (2MASS, CDS Cat. ). The total number of optical sources falling in the Chandra FOV is 8956, while the Damiani et al. (2004, ApJ, 608, 781) Catalog contains 884 X-ray sources, who concluded that at least 90% of the X-ray sources are very probable cluster members. To cross-correlate the X-ray and optical catalogs, the authors used a matching distance of < 4 sigmaX, where sigmaX is the the X-ray positional error, or 1.5", whichever is smaller, after a systematic shift between the X-ray and WFI positions of 0.2" in RA and -0.26" in Dec had been included. This resulted in a number of multiple identifications, among which 4 turned into unique identifications when a reduced distance of 1.5" was used. This finally resulted in 721 single, 44 double, and 3 triple identifications in the optical catalog; in addition, one X-ray source has 4 optical identifications, and another has 6 optical identifications. The total number of X-ray sources with WFI counterparts is therefore 770; of them, only 15 X-ray identified stars come from the Sung et al. (2000, AJ, 120, 333) Catalog and are not in the WFI Catalog. The total number of optical sources with an X-ray counterpart is 828. The agreement between X-ray and WFI optical positions is excellent in most cases, with offsets below 1". This database table was created by the HEASARC in February 2007, based on CDS table J/A+A/430/941/table5.dat This is a service provided by NASA HEASARC .
NGC 1399 Chandra X-Ray Source Catalog
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This table contains results from a wide-field study of the globular cluster (GC)/low-mass X-ray binary (LMXB) connection in the giant elliptical NGC 1399. The large field of view of the Advanced Camera for Surveys/WFC, combined with the high resolution of the Hubble Space Telescope and Chandra, allow the authors to constrain the LMXB formation scenarios in elliptical galaxies. They confirm that NGC 1399 has the highest LMXB fraction in GCs of all nearby elliptical galaxies studied so far, even though the exact value depends on galactocentric distance due to the interplay of a differential GC versus galaxy light distribution and the GC color dependence. In fact, LMXBs are preferentially hosted by bright, red GCs out to > 5 R
eff of the galaxy light. The finding that GCs hosting LMXBs follow the radial distribution of their parent GC population argues against the hypothesis that the external dynamical influence of the galaxy affects the LMXB formation in GCs. On the other hand, field-LMXBs closely match the host galaxy light, thus indicating that they are originally formed in situ and not inside GCs. The authors measure GC structural parameters, finding that the LMXB formation likelihood is influenced independently by mass, metallicity, and GC structural parameters. In particular, the GC central density plays a major role in predicting which GCs host accreting binaries. Finally, this analysis shows that LMXBs in GCs are marginally brighter than those in the field, and in particular the only color-confirmed GC with L
X > 10
39 erg/s shows no variability, which may indicate a superposition of multiple LMXBs in these systems. The optical data were taken with the ACS on board the HST (GO-10129), in the F606W filter. A detailed description of the HST data and source catalogs are given in Puzia T.H. et al. 2011, in preparation. The X-ray data were retrieved from the Chandra public archive (CXC). The authors selected observations 319 (ACIS-S; 2000 Jan 18) and 1472 (ACIS-I; 2003 May 26). This table contains the list of 230 X-ray sources detected in the overlap region common to Chandra ACIS-I, Chandra ACIS-S and HST ACS observation (see Fig 1 of the reference paper). Details of the X-ray source detection methodology are given in Section 2.2 of the reference paper. This table was created by the HEASARC in January 2013 based on the
CDS Catalog J/ApJ/736/90 file table3.dat. This is a service provided by NASA HEASARC .
NGC 3115 Chandra X-Ray Point Source Catalog
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This table contains some of the results from an in-depth study of low-mass X-ray binaries (LMXBs) detected in the nearby lenticular galaxy NGC 3115 using the Megasecond Chandra X-ray Visionary Project observation (total exposure time 1.1 Ms). In total the authors found 136 candidate LMXBs in the field and 49 in globular clusters (GCs) above 2-sigma detection, with 0.3-8 keV luminosity LX ~ 1036 - 1039 erg s-1. Other than 13 transient candidates, the sources overall have less long-term variability at higher luminosity, at least at LX >~ 2 x 1037 erg s-1. In order to identify the nature and spectral state of these sources, the authors compared their collective spectral properties based on single-component models (a simple power law or a multicolor disk) with the spectral evolution seen in representative Galactic LMXBs. The authors found that in the LX vs. photon index GammaPL and LX versus disk temperature kTMCD plots, most of their sources fall on a narrow track in which the spectral shape hardens with increasing luminosity below LX ~ 7 x 1037 erg s-1, but is relatively constant (GammaPL ~ 1.5 or kTMCD ~ 1.5 keV) above this luminosity, which is similar to the spectral evolution of Galactic neutron star (NS) LMXBs in the soft state in the Chandra bandpass. Therefore, the authors identified the track as the NS LMXB soft-state track and suggested sources with LX <~ 1037 erg s-1 as atolls in the soft state and those with LX >~ 1037 erg s-1 as Z sources. Ten other sources (five are transients) displayed significantly softer spectra and are probably black hole X-ray binaries in the thermal state. One of them (a persistent source) is in a metal-poor GC. The 11 Chandra observations of NGC 3115 are listed in Table 1 of the reference paper. They were made during three epochs: one in 2001,two in 2010, and nine in 2012. All observations used the imaging array of the AXAF CCD Imaging Spectrometer (ACIS). This table contains the properties of the 482 detected point sources in the merged and single Chandra ACIS observations of NGC 3115 above a 2-sigma threshold and after eliminating a number of spurious sources associated with bright streaks on the ACIS-S1 chip and (in one case) on a CCD edge. 469 of these sources (indicated by values of obs_flag = '0') have a single entry in this table, based on their properties as derived from all of the available Chandra data for that position. There are 13 transient sources (having obs_flag = 'h') for which an additional entry is provided referring to their properties in the "high state", and based on the combination of their high-state observations, as shown in Figures 3(a) - 3(d) in the reference paper. For source number 198, there is a second additional entry provided referring to its properties in the "low state", and based on the combination of its low-state observations, as shown in Figure 3(c) in the reference paper. Thus, there are 496 entries (rows) in this table, i.e., 482 + 13 + 1. This table was created by the HEASARC in August 2015 based on the union of the machine-readable versions of Table 3 (the master source catalog) and Table 4 (the source counts, fluxes and hardness ratios in the merged observations) that were obtained from the ApJ web site. It does not contain the source counts and fluxes in the individual observations which were given in Table 5 of the reference paper. This is a service provided by NASA HEASARC .