- ID:
- ivo://CDS.VizieR/J/ApJS/209/27
- Title:
- MYStIX: the Chandra X-ray sources
- Short Name:
- J/ApJS/209/27
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Massive Young star-forming complex Study in Infrared and X-ray (MYStIX) uses data from the Chandra X-Ray Observatory to identify and characterize the young stellar populations in 20 Galactic (d<4kpc) massive star-forming regions. Here, the X-ray analysis for Chandra ACIS-I observations of 10 of the MYStIX fields is described, and a catalog of >10000 X-ray sources is presented. In comparison to other published Chandra source lists for the same regions, the number of MYStIX-detected faint X-ray sources in a region is often doubled. While the higher catalog sensitivity increases the chance of false detections, it also increases the number of matches to infrared stars. X-ray emitting contaminants include foreground stars, background stars, and extragalactic sources. The X-ray properties of sources in these classes are discussed.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/618/L83
- Title:
- Narrow iron K{alpha} lines in AGN
- Short Name:
- J/ApJ/618/L83
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We assemble a sample consisting of 66 active galactic nuclei (AGNs) from the literature (Page et al., 2004MNRAS.347..316P) and from the XMM-Newton archive in order to investigate the origin of the 6.4keV narrow iron K{alpha} line (NIKAL). The X-ray Baldwin effect of the NIKAL is confirmed in this sample.
- ID:
- ivo://CDS.VizieR/J/ApJS/207/36
- Title:
- 2nd MAXI/GSC catalog in high galactic-latitude sky
- Short Name:
- J/ApJS/207/36
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of high Galactic-latitude (|b|>10{deg}) X-ray sources detected in the first 37 months of data of the Monitor of All-sky X-ray Image/Gas Slit Camera (MAXI/GSC). To achieve the best sensitivity, we develop a background model of the GSC that well reproduces the data based on the detailed on-board calibration. Source detection is performed through image fits with a Poisson likelihood algorithm. The catalog contains 500 objects detected with significances of s_D,4-10keV_>=7 in the 4-10keV band. The limiting sensitivity is ~7.5x10^-12^erg/cm2/s (~0.6mCrab) in the 4-10keV band for 50% of the survey area, which is the highest ever achieved in an all-sky survey mission covering this energy band. We summarize the statistical properties of the catalog and results from cross matching with the Swift/BAT 70 month catalog (Cat. J/ApJS/207/19), the meta-catalog of X-ray detected clusters of galaxies (MCXC; Cat. J/A+A/534/A109), and the MAXI/GSC 7 month catalog (Cat. J/PASJ/63/S677). Our catalog lists the source name (2MAXI), position and its error, detection significances and fluxes in the 4-10keV and 3-4keV bands, the hardness ratio, and the basic information of the likely counterpart available for 296 sources.
- ID:
- ivo://CDS.VizieR/J/MNRAS/471/4990
- Title:
- Nearby galaxy clusters X-ray point sources
- Short Name:
- J/MNRAS/471/4990
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this work, we studied 10 nearby (z<=0.038) galaxy clusters to understand possible interactions between hot plasma and member galaxies. A multi-band source detection was applied to detect point-like structures within the intra-cluster medium. We examined the spectral properties of a total of 391 X-ray point sources within each cluster's potential well. log N versus log S was studied in the energy range 2-10 keV to measure X-ray overdensities. Optical overdensities were also calculated to solve suppression/triggering phenomena for nearby galaxy clusters. X-ray and optical flux/luminosity properties (X/O, L_X_/L_B_ and L_X_/L_K_) were investigated for optically identified member galaxies. The X-ray luminosities of our point sources were found to be faint [40.08<=log(L_X_)<=42.39erg/s]. The luminosity range of point sources reveals possible contributions to X-ray emission from low-luminosity active galactic nuclei, X-ray binaries and star formation. We estimated ~2 times higher X-ray overdensities from galaxies within galaxy clusters compared to fields. Our results demonstrate that optical overdensities are much higher than X-ray overdensities at a cluster's centre, whereas X-ray overdensities increase through the outskirts of clusters. We conclude that high pressure from a cluster's centre affects the balance of galaxies and they lose a significant amount of their fuel. As a result, the clustering process quenches the X-ray emission of the member galaxies. We also find evidence that the existence of X-ray bright sources within a cluster environment can be explained by two main phenomena: contributions from off-nuclear sources and/or active galactic nucleus (AGN) triggering caused by galaxy interactions rather than AGN fuelling.
- ID:
- ivo://CDS.VizieR/J/ApJ/667/963
- Title:
- Near-infrared photometry of Carina nebula
- Short Name:
- J/ApJ/667/963
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have carried out near-infrared (NIR) imaging observations of the Carina Nebula for an area of ~400arcmin^29 including the clusters Trumpler 14 and Trumpler 16, with 10sigma limits of J~18.5, H~17.5, and Ks ~16.5mag. A total of 544 Class II candidates, 11 Class I candidates, and 40 red (H-Ks>2) sources have been found.
- ID:
- ivo://CDS.VizieR/J/MNRAS/368/534
- Title:
- Near-infrared study of CIZA J1324.7-5736
- Short Name:
- J/MNRAS/368/534
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the result of a deep near-infrared survey of the newly identified X-ray luminous cluster of galaxies CIZA J1324.7-5736 in the Great Attractor (GA) region. In a 35x35arcmin^2^ region, 111 galaxy candidates with r(Ks20)>3arcsec are identified.
- ID:
- ivo://CDS.VizieR/J/ApJ/721/1663
- Title:
- Near-IR matches of X-ray sources in Gal. Center
- Short Name:
- J/ApJ/721/1663
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Chandra X-ray Observatory has now discovered nearly 10000 X-ray point sources in the 2{deg}x0.8{deg} region around the Galactic Center. The sources are likely to be a population of accreting binaries in the Galactic Center, but little else is known of their nature. We obtained JHKs imaging of the 17'x17' region around Sgr A*, an area containing 4339 of these X-ray sources, with the ISPI camera on the Cerro Tololo Inter-American Observatory (CTIO) 4m telescope. We cross-correlate the Chandra and ISPI catalogs to find potential IR counterparts to the X-ray sources. The extreme IR source crowding in the field means that it is not possible to establish the authenticity of the matches with astrometry and photometry alone. We find 2137 IR/X-ray astrometrically matched sources: statistically, we estimate that our catalog contains 289+/-13 true matches to soft X-ray sources and 154+/-39 matches to hard X-ray sources. However, the fraction of true counterparts to candidate counterparts for hard sources is just 11%, compared to 60% for soft sources, making hard source NIR matches particularly challenging for spectroscopic follow-up. We calculate a color-magnitude diagram (CMD) for the matches to hard X-ray sources, and find regions where significant numbers of the IR matches are real. We use their CMD positions to place limits on the absolute Ks-band magnitudes of the potential NIR counterparts to hard X-ray sources. We find regions of the counterpart CMD with 9+/-3 likely Wolf-Rayet/supergiant binaries (with four spectroscopically confirmed in the literature) as well as 44+/-13 candidates that could consist of either main-sequence high mass X-ray binaries or red giants with an accreting compact companion. In order to aid spectroscopic follow-up, we sort the candidate counterpart catalog on the basis of IR and X-ray properties to determine which source characteristics increase the probability of a true match. We find a set of 98 IR matches to hard X-ray sources with reddenings consistent with GC distances which have a 45% probability of being true counterparts.
- ID:
- ivo://CDS.VizieR/J/A+A/645/A95
- Title:
- NEP raster ROSAT X-ray/Optical catalog
- Short Name:
- J/A+A/645/A95
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The North-Ecliptic Pole is an important region for extragalactic surveys. Deep/wide contiguous surveys are being performed by several space observatories. We analyse all ROSAT pointed and survey observations within 40deg^2^ around the NEP, restricting the field-of-view to the inner 30' radius. We obtain an X-ray catalogue of 805 sources with 0.5-2keV fluxes >2.9*10^-15^erg/cm^2^/s, a factor of three deeper than the ROSAT All-Sky Survey in this field. The sensitivity and angular resolution of our data are comparable to the eROSITA All-Sky Survey expectations. The 50% position error radius of the sample of X-ray sources is ~10". We use HEROES optical and near-infrared imaging photometry from Subaru and CFHT telescopes together with literature catalogues and a new deep and wide Spitzer survey in the field to identify X-ray sources and calculate photometric redshifts for the candidate counterparts. In particular we utilize mid-IR colours to identify AGN X-ray counterparts. Despite relatively large error circles and faint counterparts, confusion and systematic errors, we obtain a rather reliable catalogue of 766 optical counterparts, redshifts and optical classifications. We find a new population of luminous absorbed X-ray AGN at large redshifts, not recognized in previous X-ray surveys, but identified in our work due to the unique combination of survey solid angle, X-ray sensitivity and multiwavelength photometry. We also use the WISE and Spitzer photometry to identify a sample of 185 AGN selected purely through mid-IR colours, most of which are not detected by ROSAT. Their redshifts and upper limits to X-ray luminosity and X-ray-to-optical flux ratios are even higher than for the new class of X-ray selected luminous type 2 AGN (AGN2); they are probably a natural extension of this sample. This unique dataset is important as a reference sample for future deep surveys in the NEP region, in particular for eROSITA and also for Euclid and SPHEREX. We predict that most of the absorbed distant AGN should be readily picked up by eROSITA, but they require sensitive mid-IR imaging to be recognized as optical counterparts.
- ID:
- ivo://CDS.VizieR/J/ApJ/578/405
- Title:
- Neutron stars in NGC 5139
- Short Name:
- J/ApJ/578/405
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Chandra/ACIS-I detectors observed NGC 5139 in imaging mode for two continuous periods (2000 January 24 02:15-09:46 and January 25 04:33-17:24 TT) for a total exposure of ~68.6ks. We combined the two observations and analyzed them as one. We searched for point sources using CELLDETECT, using only the 0.1-2.5keV energy range, excluding regions less than 16 pixels from the detector edges and keeping only sources with signal-to-noise ratio (S/N)>5.0. We find 40 X-ray point sources over the four ACIS-I chips and chip S2 of ACIS-S, which are numbered in order of decreasing S/N in Table 1.
- ID:
- ivo://CDS.VizieR/J/AJ/145/132
- Title:
- New catalog of 1578 {delta} Scuti stars
- Short Name:
- J/AJ/145/132
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present statistical characteristics of 1578 {delta} Scuti stars including nearby field stars and cluster member stars within the Milky Way. We obtained 46% of these stars (718 stars) from work by Rodriguez and collected the remaining 54% of stars (860 stars) from other literature. We updated the entries with the latest information of sky coordinates, color, rotational velocity, spectral type, period, amplitude, and binarity. The majority of our sample is well characterized in terms of typical period range (0.02-0.25days), pulsation amplitudes (<0.5mag), and spectral types (A-F type). Given this list of {delta} Scuti stars, we examined relations between their physical properties (i.e., periods, amplitudes, spectral types, and rotational velocities) for field stars and cluster members, and confirmed that the correlations of properties are not significantly different from those reported in Rodriguez's work. All the {delta} Scuti stars are cross-matched with several X-ray and UV catalogs, resulting in 27 X-ray and 41 UV-only counterparts. These counterparts are interesting targets for further study because of their uniqueness in showing {delta} Scuti-type variability and X-ray/UV emission at the same time. The compiled catalog can be accessed through the Web interface http://stardb.yonsei.ac.kr/DeltaScuti.
