- ID:
- ivo://CDS.VizieR/J/ApJ/716/348
- Title:
- The XMM-Newton survey of the COSMOS field
- Short Name:
- J/ApJ/716/348
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the final optical identifications of the medium-depth (~60ks), contiguous (2deg^2^) XMM-Newton survey of the COSMOS field. XMM-Newton has detected ~1800 X-ray sources down to limiting fluxes of ~5x10^-16^, ~3x10^-15^, and ~7x10^-15^erg/cm^2^/s in the 0.5-2keV, 2-10keV, and 5-10keV bands, respectively (~1x10^-15^, ~6x10^-15^, and ~1x10^-14^erg/cm^2^/s, in the three bands, respectively, over 50% of the area). The work is complemented by an extensive collection of multiwavelength data from 24um to UV, available from the COSMOS survey, for each of the X-ray sources, including spectroscopic redshifts for >~50% of the sample, and high-quality photometric redshifts for the rest. The XMM and multiwavelength flux limits are well matched: 1760 (98%) of the X-ray sources have optical counterparts, 1711 (~95%) have IRAC counterparts, and 1394 (~78%) have MIPS 24um detections. Spectroscopically identified obscured and unobscured AGNs, as well as normal and star-forming galaxies, present well-defined optical and infrared properties. We devised a robust method to identify a sample of ~150 high-redshift (z>1), obscured AGN candidates for which optical spectroscopy is not available.
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- ID:
- ivo://CDS.VizieR/J/A+A/469/799
- Title:
- Torun catalog of post-AGB and related objects
- Short Name:
- J/A+A/469/799
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- With the ongoing AKARI infrared sky survey, of much greater sensitivity than IRAS, a wealth of post-AGB objects may be discovered. It is thus time to organize our present knowledge of known post-AGB stars in the galaxy with a view to using it to search for new post-AGB objects among AKARI sources. We searched the literature available on the NASA Astrophysics Data System up to 1 October 2006, and defined criteria for classifying sources into three categories: very likely, possible and disqualified post-AGB objects. The category of very likely post-AGB objects is made up of several classes. We have created an evolutionary, on-line catalogue of Galactic post-AGB objects, to be referred to as the Torun catalogue of Galactic post-AGB and related objects. The present version of the catalogue contains 326 very likely, 107 possible and 64 disqualified objects. For the very likely post-AGB objects, the catalogue gives the available optical and infrared photometry, infrared spectroscopy and spectral types, and links to finding charts and bibliography.
- ID:
- ivo://CDS.VizieR/I/232
- Title:
- Toulouse AC Zone Data Reduced to ACRS
- Short Name:
- I/232
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The U.S. Naval Observatory is in the process of making new reductions of the Astrographic Catalogue (AC) using a modern reference system, the ACRS, which represents the system of the FK5. The data from the Toulouse Zone, whose plates are centered between declinations +5 and +11 degrees (eq. 1900), have been analyzed for scale, rotation, tilt, coma, magnitude equation, radial distortion and distortions introduced by the use of reseaux in the Carte du Ciel program. The result is a positional catalog of almost 270,000 stars on eq. J2000.0, epoch of observation. Additionally, all stars have been matched with the Tycho Input Catalog (revised); those numbers have been added for additional identification purposes.
- ID:
- ivo://CDS.VizieR/J/ApJ/761/162
- Title:
- Tycho-2 stars in Galactic Bulge Survey
- Short Name:
- J/ApJ/761/162
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We identify 69 X-ray sources discovered by the Galactic Bulge Survey (GBS) that are coincident with or very close to bright stars in the Tycho-2 catalog. Additionally, two other GBS sources are resolved binary companions to Tycho-2 stars where both components are separately detected in X-rays. Most of these are likely to be real matches, but we identify nine objects with large and significant X-ray-to-optical offsets as either detections of resolved binary companions or chance alignments. We collate known spectral types for these objects, and also examine Two Micron All Sky Survey colors, variability information from the All-Sky Automated Survey, and X-ray hardness ratios for the brightest objects. Nearly a third of the stars are found to be optically variable, divided roughly evenly between irregular variations and periodic modulations. All fall among the softest objects identified by the GBS. The sample forms a very mixed selection, ranging in spectral class from O9 to M3. In some cases, the X-ray emission appears consistent with normal coronal emission from late-type stars, or wind emission from early-types, but the sample also includes one known Algol, one W UMa system, two Be stars, and several X-ray bright objects likely to be coronally active stars or binaries. Surprisingly, a substantial fraction of the spectroscopically classified, non-coincidental sample (12 out of 38 objects) have late B or A type counterparts. Many of these exhibit redder near-IR colors than expected for their spectral type and/or variability, and it is likely that the X-rays originate from a late-type companion star in most or all of these objects.
- ID:
- ivo://CDS.VizieR/J/AJ/143/41
- Title:
- UBVIc CCD photometry of star clusters Tr14 and Tr16
- Short Name:
- J/AJ/143/41
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new UBVIc CCD photometry of the young open clusters Trumpler 14 (Tr 14) and Trumpler 16 (Tr 16) in the {eta} Carina Nebula (NGC 3372). We also identify the optical counterpart of Chandra X-ray sources and Two Micron All Sky Survey point sources. The members of the clusters were selected from the proper-motion study, spectral types, reddening characteristics, and X-ray or near-IR excess emission. An abnormal reddening law R_V,cl_=4.4+/-0.2 was obtained for the stars in the {eta} Carina Nebula using the 141 early-type stars with high proper-motion membership probability (P_{mu}_>=70%). We determined the distance to each cluster and conclude that Tr 14 and Tr 16 have practically the same distance modulus of V_0_-M_V_=12.3+/-0.2mag (d=2.9+/-0.3kpc). The slope of the initial mass function was determined to be {Gamma}=-1.3+/-0.1 for Tr 14, {Gamma}=-1.3+/-0.1 for Tr 16, and {Gamma}=-1.4+/-0.1 for all members in the observed region for the stars with log m>=0.2. We also estimated the age of the clusters to be about 1-3Myr from the evolutionary stage of evolved stars and low-mass pre-main-sequence stars.
- ID:
- ivo://CDS.VizieR/J/A+AS/128/131
- Title:
- UBV photometry of NGC 2323
- Short Name:
- J/A+AS/128/131
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- UBV and DDO photoelectric photometry in the field of the open cluster NGC 2323 is presented. The analysis yields 109 probable members; one of them being a red giant, and 3 possible members. The basic cluster parameters are derived. NGC 2323 appears not to be physically connected to the CMa OB1 association.
- ID:
- ivo://CDS.VizieR/J/AJ/143/46
- Title:
- UBV photometry of stars in Berkeley 55
- Short Name:
- J/AJ/143/46
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present UBV photometry of the highly reddened and poorly studied open cluster Berkeley 55 (= C 2115+515), revealing an important population of B-type stars and several evolved stars of high luminosity. Intermediate-resolution far-red spectra of several candidate members confirm the presence of one F-type supergiant and six late supergiants or bright giants. The brightest blue stars are mid-B giants. Spectroscopic and photometric analyses indicate an age 50+/-10Myr. The cluster is located at a distance d~4kpc, consistent with other tracers of the Perseus Arm in this direction. Berkeley 55 is thus a moderately young open cluster with a sizable population of candidate red (super)giant members, which can provide valuable information about the evolution of intermediate-mass stars.
- ID:
- ivo://CDS.VizieR/I/231
- Title:
- Uccle AC Zone Data Reduced to ACRS
- Short Name:
- I/231
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The U.S. Naval Observatory is in the process of making new reductions of the Astrographic Catalogue (AC) using a modern reference system, the ACRS, which represents the system of the FK5. The data from the Uccle Zone, whose plates are centered between declinations +34 and +35 degrees (eq. 1900), have been analyzed for scale, rotation, tilt, coma, magnitude equation, radial distortion and distortions introduced by the use of reseaux in the Carte du Ciel program. The result is a positional catalog of over 117,000 stars on eq. J2000.0, epoch of observation. Additionally, all stars have been matched with the Tycho Input Catalog (revised); those numbers have been added for additional identification purposes.
- ID:
- ivo://CDS.VizieR/J/ApJS/209/10
- Title:
- UGSs. V. kernel approach
- Short Name:
- J/ApJS/209/10
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Nearly one-third of the {gamma}-ray sources detected by Fermi are still unidentified, despite significant recent progress in this area. However, all of the {gamma}-ray extragalactic sources associated in the second Fermi-LAT catalog have a radio counterpart. Motivated by this observational evidence, we investigate all the radio sources of the major radio surveys that lie within the positional uncertainty region of the unidentified {gamma}-ray sources (UGSs) at a 95% level of confidence. First, we search for their infrared counterparts in the all-sky survey performed by the Wide-field Infrared Survey Explorer (WISE) and then we analyze their IR colors in comparison with those of the known {gamma}-ray blazars. We propose a new approach, on the basis of a two-dimensional kernel density estimation technique in the single [3.4]-[4.6]-[12]{mu}m WISE color-color plot, replacing the constraint imposed in our previous investigations on the detection at 22{mu}m of each potential IR counterpart of the UGSs with associated radio emission. The main goal of this analysis is to find distant {gamma}-ray blazar candidates that, being too faint at 22{mu}m, are not detected by WISE and thus are not selected by our purely IR-based methods. We find 55 UGSs that likely correspond to radio sources with blazar-like IR signatures. An additional 11 UGSs that have blazar-like IR colors have been found within the sample of sources found with deep recent Australia Telescope Compact Array observations.
- ID:
- ivo://CDS.VizieR/J/ApJ/836/34
- Title:
- 24um excesses in clusters & membership of NGC2244
- Short Name:
- J/ApJ/836/34
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We characterize the first 40 Myr of evolution of circumstellar disks through a unified study of the infrared properties of members of young clusters and associations with ages from 2Myr up to ~40Myr: NGC1333, NGC1960, NGC2232, NGC2244, NGC2362, NGC2547, IC348, IC2395, IC4665, ChamaeleonI, OrionOB1a and OB1b, Taurus, the {beta} Pictoris Moving Group, {rho} Ophiuchi, and the associations of Argus, Carina, Columba, Scorpius-Centaurus, and Tucana-Horologium. Our work features: (1) a filtering technique to flag noisy backgrounds; (2) a method based on the probability distribution of deflections, P(D), to obtain statistically valid photometry for faint sources; and (3) use of the evolutionary trend of transitional disks to constrain the overall behavior of bright disks. We find that the fraction of disks three or more times brighter than the stellar photospheres at 24{mu}m decays relatively slowly initially and then much more rapidly by ~10Myr. However, there is a continuing component until ~35Myr, probably due primarily to massive clouds of debris generated in giant impacts during the oligarchic/chaotic growth phases of terrestrial planets. If the contribution from primordial disks is excluded, the evolution of the incidence of these oligarchic/chaotic debris disks can be described empirically by a log-normal function with the peak at 12-20Myr, including ~13% of the original population, and with a post-peak mean duration of 10-20Myr.
