- ID:
- ivo://nasa.heasarc/ic1396acxo
- Title:
- IC1396A&Trumpler37ClusterChandraX-RayPointSourceCatalog
- Short Name:
- IC1396ACXO
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- Rich, young stellar clusters produce H II regions whose expansion into the nearby molecular cloud is thought to trigger the formation of new stars. However, the importance of this mode of star formation is uncertain. This investigation seeks to quantify triggered star formation (TSF) in IC 1396A (aka the Elephant Trunk Nebula), a bright-rimmed cloud (BRC) on the periphery of the nearby giant HII region IC 1396 produced by the Trumpler 37 cluster. X-ray selection of young stars from Chandra X-ray Observatory data is combined with existing optical and infrared surveys to give a more complete census of the TSF population. Over 250 young stars in and around IC 1396A are identified; this doubles the previously known population. A spatio-temporal gradient of stars from the IC 1396A cloud towards the primary ionizing star HD 206267 is found. The current project consists of two Chandra-ACIS X-ray observations of IC 1396A, a Guaranteed Time observation (ObsID No. 11807 obtained on 2010 March 31; PI: Garmire) and a Guest Observer observation (ObsID No. 10990 obtained on 2010 June 9; PI: Getman). Both observations were pointed at the head of the globule but had different roll angles. For each observation, the authors considered only results arising from the imaging array (ACIS-I) of four abutted 1024 x 1024 pixel front-side illuminated charge-coupled devices (CCDs) covering about 17 x 17 arcmin<sup>2</sup> on the sky, Similar to the Chandra catalog of X-ray sources in the Carina Nebula (Broos et al. 2011, ApJS, 194, 2), this list of candidate sources in IC 1396A is trimmed to omit sources with fewer than 3 total source counts (the sum of the net counts and the background counts, NC + BC < 3) and the probability for being a background fluctuation greater than 1% (prob_no_src > 0.01). The final catalog comprises 415 X-ray sources, roughly half of which sources are extragalactic with extremely optically faint counterparts (Section 3.2 of the reference paper), and the rest are young stars associated with the Trumpler 37 and IC 1396A star-forming regions. UVR<sub>c</sub> I<sub>c</sub> observations were carried out with the 1.2-m telescope at the Fred Lawrence Whipple Observatory (FLWO), using the 4Shooter CCD array, between 2000 September and 2002 September. 4Shooter is an array of four CCDs, covering a square of 25 arcminutes on the side. Two 4Shooter fields were taken to cover an ~45 x 25 arcmin<sup>2</sup> area centered on the star HD 206267. The FLWO fields contain the whole ACIS field, except for a small gap in between the four CCDs of 4Shooter. All but a few Chandra stars were observed in 2000 September. UVR<sub>J</sub> I<sub>J</sub> observations of Trumpler 37/IC 1396A were obtained in service mode during three nights in 2007 June 9-11 using the wide-field camera, LAICA, mounted on the 3.5-m telescope in Calar Alto, Spain. LAICA is a 2 x 2 mosaic of four CCDs, each covering a 15.3 x 15.3 arcmin<sup>2</sup> field of view (FOV) with a large gap of 15.3 x 15.3 arcmin<sup>2</sup> in between. The project combines four LAICA pointings covering an ~45 x 45 arcmin<sup>2</sup> area around HD 206267, including nearly the entire ACIS field. The Spitzer observation was obtained on 2003 December 20 with the IRAC detector in all four IRAC channels (3.6, 4.5, 5.8 and 8.0 micron). Two adjacent fields subtending ~37 x 42 arcmin<sup>2</sup> in channel pairs 3.6/5.8 micron and 4.5/8.0 micron were centered on Trumpler 37. To reduce unnecessary data processing the authors analyzed only a portion of the original data that encompassed the Chandra-ACIS field with a coverage of ~19 x 19 arcmin<sup>2</sup> area in all four channels centered on Rim A of the IC 1396A globule. This covers 93% of the ACIS field omitting its north-western and south-western edges. An automated cross-correlation between the Chandra source positions and the optical-IR source positions was made using a search radius of 2 arcseconds within ~6 arcminutes of the ACIS field center, and a search radius of 3.5 arcseconds in the outer regions of the ACIS field where the X-ray source positions are more uncertain due to the deterioration of the Chandra telescope PSF. This was followed by a careful visual examination of each source in both bands to remove dubious sources and associations. This table was created by the HEASARC in April 2017 based upon the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/MNRAS/426/2917">CDS Catalog J/MNRAS/426/2917</a> files table1.dat, table2.dat, and table3.dat. This is a service provided by NASA HEASARC .
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- ID:
- ivo://nasa.heasarc/ic348cxo2
- Title:
- IC 348 Chandra X-Ray Point Source Catalog 2
- Short Name:
- IC348CXO2
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- IC 348 is a nearby (~ 310 pc), young (~ 2 - 3 Myr) open cluster with > 300 members identified from optical and infrared observations. The authors studied the properties of the coronae of the young low-mass stars in IC 348, combining X-ray and optical/infrared data. The four existing Chandra observations of IC 348 were merged, thus providing a deeper and spatially more complete X-ray view than previous X-ray studies of the cluster. The authors compiled a comprehensive catalog of IC 348 members taking into account recent updates to the cluster census. Their data collection comprises fundamental stellar parameters, infrared excess indicating the presence of disks, H-alpha emission as a tracer of chromospheric emission or accretion, and mass accretion rates. The authors have detected 290 X-ray sources in four merged Chandra exposures, of which 185 are associated with known cluster members corresponding to a detection rate of ~ 60% for the cluster members of IC 348 identified in optical/infrared studies. According to the most recent spectral classification of IC 348 members, only four of the X-ray sources are brown dwarfs (spectral type M6 and later). The detection rate is highest for diskless Class III stars and increases with stellar mass. This may be explained with higher X-ray luminosities for higher mass and later evolutionary stage that is evident in the X-ray luminosity functions. In particular, the authors find that for the lowest examined masses (0.1 M<sub>sun</sub> - 0.25 M<sub>sun</sub>) there is a difference between the X-ray luminosity functions of accreting and non-accreting stars (classified on the basis of their H-alpha emission strength) as well as those of disk-bearing and diskless stars (classified on the basis of the slope of the spectral energy distribution). These differences disappear for higher masses. This is related to the finding that the L<sub>x</sub>/L<sub>bol</sub> ratio is non-constant across the mass/luminosity sequence of IC 348 with a decrease towards lower luminosity stars. Their analysis of an analogous stellar sample in the Orion Nebula Cluster suggests to the authors that the decline of L<sub>x</sub>/L<sub>bol</sub> for young stars at the low-mass end of the stellar sequence is likely universal. X-ray fluxes are presented for all (185) known optical/infrared IC348 members which were observed and detected by Chandra. The basic source parameters for all X-ray sources, i.e., including an additional 105 sources not associated with known IC 348 members, are given. The X-ray flux upper limits for 129 IC 348 members which were observed but not detected by Chandra (present in the as published version of Table 3 from the reference paper) are not included in this HEASARC representation of the data given in Tables 3 and 7 from the reference paper. Thus, this table contains 290 (185 + 105) rows, one for each X-ray source (IC 348 member or not) detected by Chandra in the direction of IC 348. This HEASARC table was created in February 2012 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/537/A135">CDS Catalog J/A+A/537/A135</a> files table3.dat and table7.dat. It lists the X-ray counts and other properties for the 290 Chandra X-ray sources which were listed in table7.dat. It does not include the X-ray flux upper limits for 129 non-detected IC 348 members which were given in table3.dat, so only the X-ray fluxes and luminosities for the 185 X-ray detected IC 348 members given in table3.dat are included in this table. Notice that in the CDS version there were 2 duplicate entries in table3.dat. Some of the values for the name parameter in the HEASARC's implementation of this table were corrected in April 2018. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/ic10cxo
- Title:
- IC 10 Chandra X-ray Point Source Catalog
- Short Name:
- IC10CXO
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The authors monitored the Cassiopeia dwarf galaxy (IC 10) in a series of 10 Chandra ACIS-S observations to capture its variable and transient X-ray source population, which is expected to be dominated by High Mass X-ray Binaries (HMXBs). They present a sample of 21 X-ray sources that are variable between observations at the 3-sigma level, from a catalog of 110 unique point sources (the HEASARC notes that there are actually 111 sources in the CDS version of the catalog from which this HEASARC table originates). The authors find four transients (flux variability ratio greater than 10) and a further eight objects with ratios >5. The observations span the years 2003-2010 and reach a limiting luminosity of >10<sup>35</sup> erg/s, providing sensitivity to X-ray binaries in IC 10 as well as flare stars in the foreground Milky Way. The nature of the variable sources is investigated from light curves, X-ray spectra, energy quantiles, and optical counterparts. The purpose of this study is to discover the composition of the X-ray binary population in a young starburst environment. IC 10 provides a sharp contrast in stellar population age (<10 million years) when compared to the Magellanic Clouds (40-200 Myr) where most of the known HMXBs reside. The authors find 10 strong HMXB candidates, 2 probable background active galactic nuclei, 4 foreground flare-stars or active binaries, and 5 not yet classifiable sources. Complete classification of the sample requires optical spectroscopy for radial velocity analysis and deeper X-ray observations to obtain higher S/N spectra and search for pulsations. A catalog (contained in this HEASARC table) has been created and supporting data sets (the data used to create the light curves shown in Figures 3, 4 and 5 in the reference paper) are available at <a href="http://cdsarc.u-strasbg.fr/ftp/cats/J/ApJ/836/50/">http://cdsarc.u-strasbg.fr/ftp/cats/J/ApJ/836/50/</a>. A monitoring series of 7x15 ks Chandra/ACIS observations, spaced at roughly six-week intervals was obtained during 2009-2010. A pair of very deep ACIS-S3 observations (2x45ks) made in 2006 November provided a reference data set for improved source positions and spectral information. The original Wang+ (2005, MNRAS, 362, 1065) Chandra (ACIS-S3) observation of 30 ks made in 2003 was also included in this analysis. The complete listing of 10 Chandra observation identifiers (ObsIDs) comprising the data set is summarized in Table 1 of the reference paper, also shown here: <pre> MJD |Date |ObsID|Flag|Exp.|RA(J2000)Dec(J2000)|Roll|Num. Sources ks hh mm ss dd mm ss deg. 52710.7|2003 Mar 12 |03953|a |28.9|00 20 25 +59 16 55|339.27|31 54041.8|2006 Nov 2 |07082| |40.1|00 20 04 +59 16 45|223.70|48 54044.2|2006 Nov 5 |08458| |40.5|00 20 04 +59 16 45|223.70|41 55140.7|2009 Nov 5 |11080| |14.6|00 20 17 +59 17 56|226.53|19 55190.2|2009 Dec 25 |11081| | 8.1|00 20 19 +59 18 02|286.15|24 55238.5|2010 Feb 11 |11082| |14.7|00 20 23 +59 17 10|320.56|24 55290.6|2010 Apr 4 |11083| |14.7|00 20 34 +59 19 01| 10.32|25 55337.8|2010 May 21 |11084| |14.2|00 20 25 +59 20 16| 67.89|27 55397.5|2010 Jul 20 |11085| |14.5|00 20 11 +59 19 13|121.25|22 55444.6|2010 Sep 5 |11086| |14.7|00 20 15 +59 18 11|157.71|27 |2006 Nov 2-5 |57082|b |80.6|00 20 04 +59 16 45|223.70|63 </pre> Flag values as follows: <pre> a = ObsID 03953 used about half of the CCD area in subarray mode. b = Merged 2006 data set referred to as ObsID 57082 consists of the nearly contiguous ObsIDs 07082 and 08458, which had identical pointings. </pre> Roll is the spacecraft roll angle, and Num. Sources is the number of unique point sources detected in each observation after combining wavdetect lists from the soft (S: 0.3-1.5 keV), broad (B: 0.3-8 keV) and hard (H: 2.5-8 keV) energy bands. This table was created by the HEASARC in November 2017 based upon the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJ/836/50">CDS Catalog J/ApJ/836/50</a> file table2.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/ic348cxo
- Title:
- IC 348 Chandra X-Ray Point Source Catalog
- Short Name:
- IC348CXO
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The authors have obtained a deep (53 ks) X-ray image of the very young stellar cluster IC 348 with the Advanced CCD Imaging Spectrometer on board the Chandra X-Ray Observatory. In this image with a sensitivity limit of ~ 1 x 10<sup>28</sup> ergs/s (more than 10 times deeper than their ROSAT images of IC 348), 215 X-ray sources were detected. While 115 of these sources can be identified with known cluster members, 58 X-ray sources are most likely new, still unidentified cluster members. About 80% of all known cluster members with masses between ~0.15 and 2 solar masses are visible as X-ray sources in the ACIS image. X-ray emission at levels of ~10<sup>28</sup> ergs/s was discovered from four of 13 known brown dwarfs and from three of 12 brown dwarf candidates in IC 348. X-ray emission was also detected from two deeply embedded objects, presumably class I protostars, south of the cluster center. Optical and infrared counterparts have been identified for most of the X-ray sources. Some 40 X-ray sources do not have optical or IR counterparts, and are most likely background (probably extragalactic) objects. This number is consistent with the expected number of extragalactic background X-ray sources based on the observed log N - log S statistics from the deep X-ray counts in the Chandra Deep Field South. This table was created by the HEASARC in January 2007 based on the merger of CDS table J/AJ/122/866/table1.dat (Table 1 from Preibisch and Zinnecker 2001) with the electronic AJ table version of Table 1 from Preibisch and Zinnecker 2002. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/ic1396ncxo
- Title:
- IC 1396N Chandra X-Ray Point Source Catalog
- Short Name:
- IC1396NCXO
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The IC 1396N cometary globule (CG) within the large nearby HII region IC 1396 has been observed with the Advanced CCD Imaging Spectrometer (ACIS) detector on board the Chandra X-Ray Observatory on 2004 October 16.93 to 17.30. 117 X-ray sources are detected, of which ~ 50-60 are likely members of the young open cluster Trumpler 37 dispersed throughout the HII region, and 25 are associated with young stars formed within the globule. Infrared photometry (2MASS and Spitzer) shows that the X-ray population is very young: 3 older Class III stars, 16 classical T Tauri stars, and 6 protostars including a Class 0/I system. The authors infer a total T Tauri population of ~ 30 stars in the globule, including the undetected population, with a star formation efficiency of 1%-4%. An elongated source spatial distribution with an age gradient oriented toward the exciting star is discovered in the X-ray population of IC 1396N, supporting similar findings in other cometary globules. The geometric and age distribution is consistent with the radiation-driven implosion (RDI) model for triggered star formation in CGs by H II region shocks. The authors include only results arising from the imaging array (ACIS-I) of four abutted 1024 x 1024 pixel front-side illuminated CCDs covering about 17' x 17' on the sky. The aim point of the array was R.A. = 21h40m42.4s, Dec. = +58d1609.7" (J2000.0) or (l,b) = (100.0, + 4.2), and the satellite roll angle (i.e., orientation of the CCD array relative to the north-south direction) was 245.9 degrees. The total net exposure time of the observation is 30 ks with no background flaring due to solar activity or data losses. This table was created by the HEASARC in February 2009 based on the electronic version of Tables 1 and 2 from the paper which were obtained from the CDS (their catalog J/ApJ/654/316 files table1.dat and table2.dat). This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/ir20126cxo
- Title:
- IRAS 20126+4104 Chandra X-Ray Point Source Catalog
- Short Name:
- IR20126CXO
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains results from Chandra ACIS-I and Karl G. Jansky Very Large Array 6-cm continuum observations of the IRAS 20126+4104 massive star-forming region. The authors detect 150 X-ray sources within the 17' x 17' ACIS-I field, and a total of 13 radio sources within the 9.2' primary JVLA beam at 4.9 GHz. Among these observations are the first 6-cm detections of the central sources reported by Hofner et al. (2007, A&A, 465, 197), namely, I20N1, I20S, and I20var. A new variable radio source is also reported in Section 3.2 of the reference paper, [MHA2015] VLA G78.1907+3.364. Searching the 2MASS archive, the authors identified 88 near-infrared (NIR) counterparts to the X-ray sources. Only four of the X-ray sources had 6-cm counterparts. Based on an NIR color-color analysis and on the Besancon simulation of Galactic stellar populations, the authors estimate that approximately 80 X-ray sources are associated with this massive star-forming region. They detect an increasing surface density of X-ray sources toward the massive protostar IRAS 20126+4104 and infer the presence of a cluster of at least 43 young stellar objects within a distance of 1.2 pc from this protostar. The authors observed the IRAS 20126+4104 region with the Chandra ACIS-I instrument on 2003 March 17 for a total exposure time of 39.35 ks. C-band (6 cm) continuum observations of the massive star-forming region IRAS 20126+4104 were conducted with the VLA operated by NRAO on 2011 August 7. These X-ray and radio data are augmented by NIR and optical archival data. For the Mid-IR wavelength regions, the authors searched the Spitzer Enhanced Imaging Products Point Source catalog. This table was created by the HEASARC in March 2016 based on the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJS/219/41">CDS catalog J/ApJS/219/41</a> files table1.dat and table5.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/lalaboocxo
- Title:
- LALA Bootes Field Chandra X-Ray Point Source Catalog
- Short Name:
- LALABOOCXO
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains the results of an analysis of a deep, 172 ks Chandra observation of the Large Area Lyman Alpha survey (LALA) Bootes field which was obtained with the Advanced CCD Imaging Spectrometer (ACIS-I) on board the Chandra X-Ray Observatory. This is one of the deepest Chandra images of the extragalactic sky, with only the 2 Ms Chandra Deep Field North (CDF-N) and the 1 Ms Chandra Deep Field South (CDF-S) observations being substantially deeper. In this table, the X-ray source catalog obtained from this image is presented, along with some results from an analysis of the X-ray source counts and optical identifications. The X-ray image is composed of two individual observations obtained in 2002 and reaches 0.5 - 2.0 and 2.0 - 10.0 keV flux limits of 1.5 x 10<sup>-16</sup> and 1.0 x 10<sup>-15</sup> ergs/cm<sup>2</sup>/s, respectively, for point sources near the aim point. A total of 168 X-ray sources were detected: 160 in the 0.5 - 7.0 keV band, 132 in the 0.5 - 2.0 keV band, and 111 in the 2.0 - 7.0 keV band. Since X-ray source number 122 has two possible optical counterparts, it is listed twice, once for each counterpart, and the total number of entries in this table is this 169. The primary optical data are R-band imaging from the NOAO Deep Wide-Field Survey (NDWFS), with a limiting magnitude of R = 25.7 magnitudes, (Vega, 3-sigma detection level, and a 4" diameter aperture). Optical counterparts within 1.5" or the 3-sigma X-ray positional uncertainties, whichever was larger, were detected above this level in the R band for 144 of the 168 X-ray sources. At least 90% of the optical counterparts should be the correct matches, and, at worst, there might be ~14 false matches. This table was created by the HEASARC in March 2007 based on the CDS table J/AJ/127/213 file table1.dat, This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/lalacetcxo
- Title:
- LALA Cetus Field Chandra X-Ray Point Source Catalog
- Short Name:
- LALACETCXO
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The 174 ks Chandra Advanced CCD Imaging Spectrometer (ACIS) exposure of the Large Area Lyman Alpha Survey (LALA) Cetus field is the second of the two deep Chandra images on LALA fields. In their paper, the authors present the Chandra X-ray sources detected in the Cetus field, along with an analysis of X-ray source counts, the stacked X-ray spectrum, and the optical identifications. A total of 188 X-ray sources were detected: 174 in the 0.5-7.0 keV band, 154 in the 0.5-2.0 keV band, and 113 in the 2.0-7.0 keV band. The X-ray source counts were derived and compared with the 172 ks exposure LALA Bootes field (available as the LALABOOCXO table in Browse). Interestingly, the authors find consistent hard-band X-ray source density, but a (36 +/- 12)% higher soft-band X-ray source density in the Cetus field. The weighted stacked spectrum of the detected X-ray sources can be fitted by a power law with photon index Gamma = 1.55. Based on the weighted stacked spectrum, the authors find that the resolved fraction of the X-ray background drops from (72 +/- 1)% at 0.5-1.0 keV to (63 +/- 4)% at 6.0-8.0 keV. The unresolved spectrum can be fitted by a power law over the range 0.5-7 keV, with a photon index Gamma = 1.22. Optical counterparts are also presented for 154 of the X-ray sources, down to a limiting magnitude of r' = 25.9 (Vega), using a deep r'-band image obtained with the MMT. This table was created by the HEASARC in October 2010 based on the CDS table J/ApJ/669/765 file table1.dat This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/lkha101cxo
- Title:
- LkH-alpha 101 Star Formation Region Chandra X-Ray Point Source Catalog
- Short Name:
- LKHA101CXO
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains some of the results from a multi-wavelength study of a partially embedded region of star formation centered on the Herbig Be star LkH-alpha 101. Using two 40 ks Chandra observations, The authors have detected 213 X-ray sources in the ~ 17' x 17' ACIS-I field. They combine the X-ray data with Two Micron All Sky Survey (2MASS) near-IR observations and Spitzer Space Telescope (SST) IRAC and MIPS 24-micron observations to obtain a complete picture of the cluster. A total of 158 of the X-ray sources have infrared counterparts. Of these, the authors find nine protostars, 48 Class II objects, five transition objects, and 72 Class III objects. From the Spitzer data, they identify an additional 10 protostars, 53 Class II objects, and four transition disk candidates which are not detected by Chandra. (These objects are not included in this HEASARC table which contains the multi-wavelength data for only the 213 detected X-ray sources). The authors obtained optical spectra of a sample of both X-ray-detected and non-X-ray-detected objects. Combining the X-ray, Spitzer, and spectral data, they obtain independent estimates of cluster distance and the total cluster size - excluding protostars. The authors obtain consistent distance estimates of 510 (+100,-40) pc and a total cluster size of 255 (+50,-25) stars. They find the Class II:III ratio is about 5:7 with some evidence that the Class III sources are spatially more dispersed. The cluster appears very young with three sites of active star formation and a median age of about 1 Myr. The field was observed by Chandra on 2005 March 6 starting at 17:16 UT for 40.2 ks of total time and 39.6 ks of the so-called good time (Chandra ObsID 5429). It was observed again on 2005 March 8 starting at 17:43 UT for essentially the same duration (Chandra ObsID 5428). The ACIS was used in the nominal imaging array (chips I0-I3) which provides a field of view of approximately 17' x 17'. The aimpoint was at RA, Dec = 04:30:14.4, +35:16:22.2 (J2000.0) with a roll angle of 281 degrees. In addition, the S2 and S3 chips were active; however, the analysis of these data is not presented here. For purposes of point-source detection, the data from the two observations were merged into a single event list following established CIAO procedures to create a merged event list. To identify point sources, photons with energies below 300 eV and above 8.0 keV were filtered out from this merged event list. This excluded energies which generally lack a stellar contribution. By filtering the data as described, contributions from hard, non-stellar sources such as X-ray binaries and active galactic nuclei (AGNs) are attenuated, as is noise. A monochromatic exposure map was generated in the standard way using an energy of 1.49 keV which is a reasonable match to the expected peak energy of the stellar sources and the Chandra mirror transmission. The CIAO tool WavDetect was then run on a series of flux-corrected images binned by 1, 2, and 4 pixels. The output source lists were combined and this resulted in the detection of 231 sources. The authors defined false detections as any sources with < 4 net counts or any sources more than 5' off-axis with < 7 net counts. By this definition, 18 of the 231 detections were rejected as false detections. A post facto check confirmed that none of these (spurious) sources had an infrared counterpart. This table was created by the HEASARC in July 2010 based on the versions of Tables 1, 2, 3, 7 and 9 from the paper which were obtained from the electronic ApJ web site. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/lmc30drcxo
- Title:
- LMC 30 Doradus Complex Chandra X-Ray Point Source Catalog
- Short Name:
- LMC30DRCXO
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains the results of a study of the X-ray point-source population of the 30 Doradus (30 Dor) star-forming complex in the Large Magellanic Cloud (LMC) using high spatial-resolution X-ray images and spatially-resolved spectra obtained with the Advanced CCD Imaging Spectrometer (ACIS) on board the Chandra X-Ray Observatory. The observation of ~21 ks was made on 1999 September 21 and placed the cluster R136 at the aim point of the ACIS Imaging Array (ACIS-I). This table lists the the X-ray sources detected in the 17' x 17' field centered on R136, the massive star cluster which lies at the center of the main 30 Dor nebula. 20 of the 32 Wolf-Rayet stars in the ACIS field are detected. The cluster R136 is resolved at the sub-arcsecond level into almost 100 X-ray sources, including many typical O3-O5 stars, as well as a few bright X-ray sources which had been previously reported. Over 2 orders of magnitude of scatter in the X-ray luminosity L<sub>x</sub> (calculated assuming a distance of 50 kpc) is seen among R136 O stars, suggesting that X-ray emission in the most massive stars depends critically on the details of wind properties and the binarity of each system, rather than reflecting the widely reported characteristic value L<sub>x</sub>/L<sub>bol</sub> ~ 10<sup>-7</sup>. Such a canonical ratio may exist for single massive stars in R136, but these data are too shallow to confirm this relationship. Through this and more recent X-ray studies of 30 Dor, the complete life cycle of a massive stellar cluster can be revealed. This HEASARC table contains both the primary high-significance X-ray sources as well as some lower-significance tentative X-ray sources. The latter sources should not be considered definitive. A subsequent Chandra observation of this field, with several times the exposure of this observation, will result in a longer, more complete list of point sources than that given in this paper. This table was created by the HEASARC in February 2007 based on the merger of electronic versions of Tables 1, 2 and 5 from the above reference which were obtained from the AJ website. It does not include the results from the spectral analysis of 49 of the X-ray sources having a photometric significance (signal-to-noise ratio) greater than 2 which are presented in Tables 3 and 4 of the reference paper. This is a service provided by NASA HEASARC .
