- ID:
- ivo://CDS.VizieR/J/AJ/144/101
- Title:
- Multiwavelength data of IRAS 20050+2720 young SFR
- Short Name:
- J/AJ/144/101
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- IRAS 20050+2720 is young star-forming region at a distance of 700pc without apparent high-mass stars. We present results of our multi-wavelength study of IRAS 20050+2720 which includes observations by Chandra and Spitzer, and Two Micron All Sky Survey and UBVRI photometry. In total, about 300 young stellar objects (YSOs) in different evolutionary stages are found. We characterize the distribution of YSOs in this region using a minimum spanning tree analysis. We newly identify a second cluster core, which consists mostly of class II objects, about 10' from the center of the cloud. YSOs of earlier evolutionary stages are more clustered than more evolved objects. The X-ray luminosity function (XLF) of IRAS 20050+2720 is roughly lognormal, but steeper than the XLF of the more massive Orion Nebula complex. IRAS 20050+2720 shows a lower N_H_/A_K_ ratio compared with the diffuse interstellar medium.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/507/1277
- Title:
- Multiwavelength photometry of CDFS X-ray sources
- Short Name:
- J/A+A/507/1277
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The co-evolution of host galaxies and the active black holes which reside in their centre is one of the most important topics in modern observational cosmology. Here we present a study of the properties of obscured active galactic nuclei (AGN) detected in the CDFS 1 Ms observation and their host galaxies. We limited the analysis to the MUSIC area, for which deep K-band observations obtained with ISAAC@VLT are available, ensuring accurate identifications of the counterparts of the X-ray sources as well as reliable determination of photometric redshifts and galaxy parameters, such as stellar masses and star formation rates. In particular, we: 1) refined the X-ray/infrared/optical association of 179 sources in the MUSIC area detected in the Chandra observation; 2) studied the host galaxies observed and rest frame colors and properties.
- ID:
- ivo://CDS.VizieR/J/A+A/392/795
- Title:
- Multi-wavelength study of 2 galaxy clusters
- Short Name:
- J/A+A/392/795
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results from optical, X-ray and radio observations of two X-ray bright (L_X_~10^45^erg/s) galaxy clusters. Abell 1451 is at redshift z=0.1989 and has line-of-sight velocity dispersion {sigma}_V_=1330km/s as measured from 57 cluster galaxies. It has regular X-ray emission without signs of substructure, a Gaussian velocity distribution, lack of a cooling flow region and significant deviations from the observed scaling laws between luminosity, temperature and velocity dispersion, indicating a possible merging shock. There is only one spectroscopically confirmed cluster radio galaxy, which is close to the X-ray peak. 1RXS J131423.6-251521 (for short RXJ1314-25) has z=0.2474 and {sigma}_V_=1100km/s from 37 galaxies. There are two distinct galaxy groups with a projected separation of ~700kpc. The velocity histogram is bi-modal with a redshift-space separation of ~1700km/s, and the X-ray emission is double peaked. Although there are no spectroscopically confirmed cluster radio galaxies, we have identified a plausible relic source candidate.
- ID:
- ivo://CDS.VizieR/J/MNRAS/391/1279
- Title:
- Multiwavelength study of NGC 7419
- Short Name:
- J/MNRAS/391/1279
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using new UBVRI H{alpha} CCD photometric observations and the archival infrared and X-ray data, we have carried out a multiwavelength study of a Perseus arm young open star cluster NGC 7419. Using XMM-Newton observations, we found several X-ray sources in the cluster region but none of the Herbig Ae/Be stars is detected in X-rays.
- ID:
- ivo://CDS.VizieR/J/PASJ/64/107
- Title:
- Multiwavelength study of NGC 281 complex
- Short Name:
- J/PASJ/64/107
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a multiwavelength study of the NGC 281 complex, which contains the young cluster IC 1590 at the center, using deep wide-field optical UBVIc photometry, slitless spectroscopy along with archival data sets in the near-infrared (NIR) and X-ray regions.
- ID:
- ivo://CDS.VizieR/J/MNRAS/425/1215
- Title:
- Multiwavelength survey of AGNs
- Short Name:
- J/MNRAS/425/1215
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We aim to study the effect of environment on the presence and fuelling of active galactic nuclei (AGNs) in massive galaxy clusters. We explore the use of different AGN detection techniques with the goal of selecting AGN across a broad range of luminosities, AGN/host galaxy flux ratios and obscuration levels. From a sample of 12 galaxy clusters at redshifts 0.5<z<0.9, we identify AGN candidates using optical variability from multi-epoch Hubble Space Telescope imaging, X-ray point sources in Chandra images and mid-infrared (IR) spectral energy distribution power-law fits through the Spitzer Infrared Array Camera channels. We find 178 optical variables, 74 X-ray point sources and 64 IR power-law sources, resulting in an average of ~25 AGN per cluster.
547. M83 X-ray sources
- ID:
- ivo://CDS.VizieR/J/A+A/410/53
- Title:
- M83 X-ray sources
- Short Name:
- J/A+A/410/53
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have identified 127 discrete sources in a Chandra ACIS observation of M 83, with a detection limit of ~3x10^36^erg/s in the 0.3-8.0keV band.
- ID:
- ivo://CDS.VizieR/J/MNRAS/414/1329
- Title:
- M82 X-ray sources long-term variability
- Short Name:
- J/MNRAS/414/1329
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate the long-term variability exhibited by the X-ray point sources in the starburst galaxy M82. By combining nine Chandra observations taken between 1999 and 2007, we detect 58 X-ray point sources within the D_25_ isophote of M82 down to a luminosity of ~10^37^erg/s. Of these 58 sources, we identify three supernova remnant candidates and one supersoft source. 26 sources in M82 exhibit long-term (i.e. days to years) flux variability and three show long-term spectral variability. Furthermore, we classify 26 sources as variables and 10 as persistent sources. Among the total 26 variables, 17 varied by a flux ratio of >3 and six are transient candidates. By comparing with other nearby galaxies, M82 shows extremely strong long-term X-ray variability that 47 per cent of the X-ray sources are variables with a flux ratio of >3. The strong X-ray variability of M82 suggests that the population is dominated by X-ray binaries.
- ID:
- ivo://CDS.VizieR/J/ApJ/833/193
- Title:
- MYStIX candidate protostars
- Short Name:
- J/ApJ/833/193
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Massive Young Star-Forming Complex in Infrared and X-ray (MYStIX) project provides a new census on stellar members of massive star-forming regions within 4kpc. Here the MYStIX Infrared Excess catalog and Chandra-based X-ray photometric catalogs are mined to obtain high-quality samples of Class I protostars using criteria designed to reduce extragalactic and Galactic field star contamination. A total of 1109 MYStIX Candidate Protostars (MCPs) are found in 14 star-forming regions. Most are selected from protoplanetary disk infrared excess emission, but 20% are found from their ultrahard X-ray spectra from heavily absorbed magnetospheric flare emission. Two-thirds of the MCP sample is newly reported here. The resulting samples are strongly spatially associated with molecular cores and filaments on Herschel far-infrared maps. This spatial agreement and other evidence indicate that the MCP sample has high reliability with relatively few "false positives" from contaminating populations. But the limited sensitivity and sparse overlap among the infrared and X-ray subsamples indicate that the sample is very incomplete with many "false negatives." Maps, tables, and source descriptions are provided to guide further study of star formation in these regions. In particular, the nature of ultrahard X-ray protostellar candidates without known infrared counterparts needs to be elucidated.
- ID:
- ivo://CDS.VizieR/J/ApJS/209/30
- Title:
- MYStIX project: Bayesian matching
- Short Name:
- J/ApJS/209/30
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Identifying the infrared counterparts of X-ray sources in Galactic plane fields such as those of the MYStIX project presents particular difficulties due to the high density of infrared sources. This high stellar density makes it inevitable that a large fraction of X-ray positions will have a faint field star close to them, which standard matching techniques may incorrectly take to be the counterpart. Instead we use the infrared data to create a model of both the field star and counterpart magnitude distributions, which we then combine with a Bayesian technique to yield a probability that any star is the counterpart of an X-ray source. In our more crowded fields, between 10% and 20% of counterparts that would be identified on the grounds of being the closest star to an X-ray position within a 99% confidence error circle are instead identified by the Bayesian technique as field stars. These stars are preferentially concentrated at faint magnitudes. Equally importantly the technique also gives a probability that the true counterpart to the X-ray source falls beneath the magnitude limit of the infrared catalog. In deriving our method, we place it in the context of other procedures for matching astronomical catalogs.
