- ID:
- ivo://CDS.VizieR/J/ApJ/837/130
- Title:
- Collinder 261 Chandra sources & optical counterparts
- Short Name:
- J/ApJ/837/130
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first X-ray study of Collinder 261 (Cr261), which at an age of 7Gyr is one of the oldest open clusters known in the Galaxy. Our observation with the Chandra X-Ray Observatory is aimed at uncovering the close interacting binaries in Cr261, and reaches a limiting X-ray luminosity of L_X_~4x10^29^erg/s (0.3-7keV) for stars in the cluster. We detect 107 sources within the cluster half-mass radius r_h_, and we estimate that among the sources with L_X_>~10^30^erg/s, ~26 are associated with the cluster. We identify a mix of active binaries and candidate active binaries, candidate cataclysmic variables, and stars that have "straggled" from the main locus of Cr261 in the color-magnitude diagram. Based on a deep optical source catalog of the field, we estimate that Cr261 has an approximate mass of 6500M_{sun}_, roughly the same as the old open cluster NGC6791. The X-ray emissivity of Cr261 is similar to that of other old open clusters, supporting the trend that they are more luminous in X-rays per unit mass than old populations of higher (globular clusters) and lower (the local neighborhood) stellar density. This implies that the dynamical destruction of binaries in the densest environments is not solely responsible for the observed differences in X-ray emissivity.
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- ID:
- ivo://CDS.VizieR/J/ApJ/720/368
- Title:
- Color-magnitude relations of galaxies in CDFs
- Short Name:
- J/ApJ/720/368
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We extend color-magnitude relations for moderate-luminosity X-ray active galactic nucleus (AGN) hosts and non-AGN galaxies through the galaxy formation epoch (z~1-4) in the Chandra Deep Field-North and Chandra Deep Field-South (CDF-N and CDF-S, respectively; jointly CDFs) surveys. This study was enabled by the deepest available X-ray data from the 2Ms CDF surveys as well as complementary ultradeep multiwavelength data in these regions. We utilized analyses of color-magnitude diagrams (CMDs) to assess the role of moderate-luminosity AGNs in galaxy evolution.
- ID:
- ivo://CDS.VizieR/J/AJ/133/2559
- Title:
- Compact radio sources in spiral galaxies. II.
- Short Name:
- J/AJ/133/2559
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the analysis of deep radio observations of the interacting galaxy system M51 from the Very Large Array, with the goal of understanding the nature of the population of compact radio sources in nearby spiral galaxies. We detect 107 compact radio sources, 64% of which have optical counterparts in a deep H{alpha} Hubble Space Telescope image. Thirteen of the radio sources have X-ray counterparts from a Chandra observation of M51. We find that six of the associated H{alpha} sources are young supernova remnants (SNRs) with resolved shells. Most of the SNRs exhibit steep radio continuum spectral indices consistent with synchrotron emission. We detect emission from the Type Ic SN 1994I nearly a decade after explosion: the emission (160+/-22uJy/beam at 20cm, 46+/-11uJy/beam at 6cm, {alpha}=-1.02+/-0.28) is consistent with light-curve models for Type Ib/Ic supernovae. We detect X-ray emission from the supernova; however, no optical counterpart is present. We report on the analysis of the Seyfert 2 nucleus in this galaxy, including the evidence for bipolar outflows from the central black hole.
- ID:
- ivo://CDS.VizieR/J/ApJ/809/10
- Title:
- Compact radio sources within 30" of Sgr A*
- Short Name:
- J/ApJ/809/10
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Recent broadband 34 and 44GHz radio continuum observations of the Galactic center have revealed 41 massive stars identified with near-IR (NIR) counterparts, as well as 44 proplyd candidates within 30" of SgrA*. Radio observations obtained in 2011 and 2014 have been used to derive proper motions of eight young stars near Sgr A*. The accuracy of proper motion estimates based on NIR observations by Lu et al. (2009ApJ...690.1463L) and Paumard et al. (2006, J/ApJ/643/1011) have been investigated by using their proper motions to predict the 2014 epoch positions of NIR stars and comparing the predicted positions with those of radio counterparts in the 2014 radio observations. Predicted positions from Lu et al. show an rms scatter of 6mas relative to the radio positions, while those from Paumard et al. show rms residuals of 20mas. We also determine the mass-loss rates of 11 radio stars, finding rates that are on average ~2 times smaller than those determined from model atmosphere calculations and NIR data. Clumpiness of ionized winds would reduce the mass loss rate of WR and O stars by additional factors of 3 and 10, respectively. One important implication of this is a reduction in the expected mass accretion rate onto Sgr A* from stellar winds by nearly an order of magnitude to a value of a few x10^-7^m_{sun}_/yr. Finally, we present the positions of 318 compact radio sources within 30" of Sgr A*, 45 of which have stellar counterparts in the NIR K_s_ (2.18{mu}m) and L' (3.8{mu}m) bands.
- ID:
- ivo://CDS.VizieR/J/BaltA/9/646
- Title:
- Compiled Catalogue of Mira-type stars
- Short Name:
- J/BaltA/9/646
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Compiled Catalogue of 1103 Mira type stars is created on the basis of the 4-th edition of the General Catalogue of Variable Stars (GCVS-4, Cat. <II/214>) and present day large high-precision catalogues based on space (Hipparcos-Tycho family catalogues: Hipparcos, Tycho-1 <I/239>, Tycho-2 (<I/259>), ACT RC (Urban et al., 1998AJ....115.2161U), TRC (Cat. <I/250>) and ground-based (CMC11 <I/256>, PPM-N <I/146>, PPM-S <I/193>, PPM-add <I/206>, Kharchenko, 1992, Kinematics and physics of celestial bodies 8, 61) data. Equatorial coordinates were taken from the source catalogues in accordance with the following priority: Hipparcos, Tycho-2, Tycho-1, CMC11, PPM, Kharchenko 1992. The proper motions in the Hipparcos system are calculated for 1041 Miras as mean weighted values of the reduced data from the source catalogues. The radial velocities obtained from absorption lines for 786 Miras were taken from nine catalogues and lists of Feast (1963MNRAS.125..367F, 1966MNRAS.132..495F), Smak and Preston (1965ApJ...142..943S), Perry and Bidelman (1965PASP...77..214P), Feast et al. (1972MNRAS.158...23F), Dean (1976AJ.....81..364D), Barnes and Fekel (1977Obs....97....1B), Feast et al. (1980MNRAS.190..227F), Barbier-Brossat and Figon (2000, Cat. <III/213>). Some radial velocities were determined from emission lines and corrected using the following formula (Ikaunieks, 1971, Long period variable stars, Zinante, Riga): V_R(abs) - V_R(em) = 0.035 * Period. For 724 Miras both proper motions and radial velocities are available. Miras in the Compiled Catalogue are sorted in the same order as in GCVS-4.
- ID:
- ivo://CDS.VizieR/J/ApJ/815/L13
- Title:
- Compton-thick AGNs from the 70-month Swift/BAT cat.
- Short Name:
- J/ApJ/815/L13
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Heavily obscured accretion is believed to represent an important stage in the growth of supermassive black holes and to play an important role in shaping the observed spectrum of the cosmic X-ray background. Hard X-ray (E>10keV) selected samples are less affected by absorption than samples selected at lower energies, and are therefore one of the best ways to detect and identify Compton-thick (CT, logN_H_>=24) active galactic nuclei (AGNs). In this letter we present the first results of the largest broadband (0.3-150keV) X-ray spectral study of hard X-ray selected AGNs to date, focusing on the properties of heavily obscured sources. Our sample includes the 834 AGNs (728 non-blazar, average redshift z~0.055) reported in the 70-month catalog of the all-sky hard X-ray Swift/Burst Alert Monitor survey. We find 55 CT AGNs, which represent 7.6_-2.1_^+1.1^% of our non-blazar sample. Of these, 26 are reported as candidate CT AGNs for the first time. We correct for selection bias and derive the intrinsic column density distribution of AGNs in the local universe in two different luminosity ranges. We find a significant decrease in the fraction of obscured Compton-thin AGNs for increasing luminosity, from 46+/-3% (for logL_14-195_=40-43.7) to 39+/-3% (for logL_14-195_=43.7-46). A similar trend is also found for CT AGNs. The intrinsic fraction of CT AGNs with logN_H_=24-25 normalized to unity in the logN_H_=20-25 range is 27+/-4%, and is consistent with the observed value obtained for AGNs located within 20Mpc.
- ID:
- ivo://CDS.VizieR/J/ApJ/761/37
- Title:
- CO observations in giant molecular clouds of M33
- Short Name:
- J/ApJ/761/37
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a giant molecular cloud (GMC) catalog of M33 (NGC598), containing 71 GMCs in total, based on wide-field and high-sensitivity CO(J=3-2) observations with a spatial resolution of 100pc using the ASTE 10m telescope. Employing archival optical data, we identify 75 young stellar groups (YSGs) from the excess of the surface stellar density, and estimate their ages by comparing with stellar evolution models. A spatial comparison among the GMCs, YSGs, and H II regions enable us to classify GMCs into four categories: Type A, showing no sign of massive star formation (SF); Type B, being associated only with H II regions; Type C, with both H II regions and <10Myr old YSGs; and Type D, with both H II regions and 10-30Myr YSGs. Out of 65 GMCs (discarding those at the edges of the observed fields), 1 (1%), 13 (20%), 29 (45%), and 22 (34%) are Types A, B, C, and D, respectively. We interpret these categories as stages in a GMC evolutionary sequence. Assuming that the timescale for each evolutionary stage is proportional to the number of GMCs, the lifetime of a GMC with a mass >10^5^M_{sun}_ is estimated to be 20-40Myr. In addition, we find that the dense gas fraction as traced by the CO(J=3-2)/CO(J=1-0) ratio is enhanced around SF regions. This confirms a scenario where dense gas is preferentially formed around previously generated stars, and will be the fuel for the next stellar generation. In this way, massive SF gradually propagates in a GMC until gas is exhausted.
- ID:
- ivo://CDS.VizieR/J/ApJS/197/16
- Title:
- CO observations of LMC molecular clouds (MAGMA).
- Short Name:
- J/ApJS/197/16
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the properties of an extensive sample of molecular clouds in the Large Magellanic Cloud (LMC) mapped at 11pc resolution in the CO(1-0) line. Targets were chosen based on a limiting CO flux and peak brightness as measured by the NANTEN survey. The observations were conducted with the ATNF Mopra Telescope as part of the Magellanic Mopra Assessment. We identify clouds as regions of connected CO emission and find that the distributions of cloud sizes, fluxes, and masses are sensitive to the choice of decomposition parameters.
- ID:
- ivo://CDS.VizieR/J/ApJ/774/22
- Title:
- CO observations of YSOs in NGC 1333
- Short Name:
- J/ApJ/774/22
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present observations of outflows in the star-forming region NGC 1333 using the Combined Array for Research in Millimeter-Wave Astronomy (CARMA). We combined the ^12^CO and ^13^CO (1-0) CARMA mosaics with data from the 14m Five College Radio Astronomy Observatory to probe the central, most dense, and active region of this protostellar cluster at scales from 5" to 7' (or 1000AU to 0.5pc at a distance of 235pc). We map and identify ^12^CO outflows, and along with ^13^CO data we estimate their mass, momentum, and energy. Within the 7'x7' map, the 5" resolution allows for a detailed study of morphology and kinematics of outflows and outflow candidates, some of which were previously confused with other outflow emission in the region. In total, we identify 22 outflow lobes, as well as 9 dense circumstellar envelopes marked by continuum emission, of which 6 drive outflows. We calculate a total outflow mass, momentum, and energy within the mapped region of 6M_{sun}_, 19M_{sun}_ km/s, and 7x10^44^erg, respectively. Within this same region, we compare outflow kinematics with turbulence and gravitational energy, and we suggest that outflows are likely important agents for the maintenance of turbulence in this region. In the earliest stages of star formation, outflows do not yet contribute enough energy to totally disrupt the clustered region where most star formation is happening, but have the potential to do so as the protostellar sources evolve.
- ID:
- ivo://CDS.VizieR/J/A+A/529/A104
- Title:
- Coordinates for Arp's Baade's Window stars
- Short Name:
- J/A+A/529/A104
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Identifications and coordinates for all stars in Arp's (1965ApJ...141...43A) finding chart for Baade's Window. For each star Arp's ID is presented, as are 2MASS and OGLE IDs when matches were found. All OGLE sources are in the BUL SC45 field. Coordinates are from 2MASS when available; for the remaining stars coordinates are calculated as described in the paper. All coordinates are in J2000. We include photometry and photometric errors from 2MASS (JHKs) and OGLE-II (VI); certain flags regarding the quality of the 2MASS photometry are also listed.
