Search

Start Over Capability Type Simple Cone Search
15641. The PAWS catalogs of GMCs and islands in M51
ID:
ivo://CDS.VizieR/J/ApJ/784/3
Title:
The PAWS catalogs of GMCs and islands in M51
Short Name:
J/ApJ/784/3
Date:
21 Oct 2021
Publisher:
CDS
Description:
Using data from the PdBI Arcsecond Whirlpool Survey (PAWS), we have generated the largest extragalactic giant molecular cloud (GMC) catalog to date, containing 1507 individual objects. GMCs in the inner M51 disk account for only 54% of the total ^12^CO(1-0) luminosity of the survey, but on average they exhibit physical properties similar to Galactic GMCs. We do not find a strong correlation between the GMC size and velocity dispersion, and a simple virial analysis suggests that ~30% of GMCs in M51 are unbound. We have analyzed the GMC properties within seven dynamically motivated galactic environments, finding that GMCs in the spiral arms and in the central region are brighter and have higher velocity dispersions than inter-arm clouds. Globally, the GMC mass distribution does not follow a simple power-law shape. Instead, we find that the shape of the mass distribution varies with galactic environment: the distribution is steeper in inter-arm region than in the spiral arms, and exhibits a sharp truncation at high masses for the nuclear bar region. We propose that the observed environmental variations in the GMC properties and mass distributions are a consequence of the combined action of large-scale dynamical processes and feedback from high-mass star formation. We describe some challenges of using existing GMC identification techniques for decomposing the ^12^CO(1-0) emission in molecule-rich environments, such as M51's inner disk.
15642. The PHLEK survey: oxygen & helium abundances
ID:
ivo://CDS.VizieR/J/ApJ/896/77
Title:
The PHLEK survey: oxygen & helium abundances
Short Name:
J/ApJ/896/77
Date:
11 Mar 2022
Publisher:
CDS
Description:
We present Keck NIRSPEC and Keck NIRES spectroscopy of sixteen metal-poor galaxies that have pre-existing optical observations. The near-infrared (NIR) spectroscopy specifically targets the HeI{lambda}10830{AA} emission line, due to its sensitivity to the physical conditions of the gas in HII regions. We use these NIR observations, combined with optical spectroscopy, to determine the helium abundance of sixteen galaxies across a metallicity range 12+log_10_(O/H)=7.13-8.00. This data set is combined with two other samples where metallicity and helium abundance measurements can be secured: star-forming galaxies selected from the Sloan Digital Sky Survey spectroscopic database, and existing low-metallicity systems in the literature. We calculate a linear fit to these measurements, accounting for intrinsic scatter, and report a new determination of the primordial helium number abundance, y_P_=0.0805_-0.0017_^+0.0017^, which corresponds to a primordial helium mass fraction Y_P_=0.2436_-0.0040_^+0.0039^. Using our determination of the primordial helium abundance in combination with the latest primordial deuterium measurement, (D/H)_P_x10^5^=2.527+/-0.030, we place a bound on the baryon density {Omega}_b_h^2^=0.0215_-0.0005_^+0.0005^ and the effective number of neutrino species N_eff_=2.85_-0.25_^+0.28^. These values are in 1.3{sigma} agreement with those deduced from the Planck satellite observations of the temperature fluctuations imprinted on the cosmic microwave background.
15643. The Phoenix Survey
ID:
ivo://CDS.VizieR/J/MNRAS/306/708
Title:
The Phoenix Survey
Short Name:
J/MNRAS/306/708
Date:
21 Oct 2021
Publisher:
CDS
Description:
Using a deep Australia Telescope Compact Array (ATCA) radio survey covering an area of ~3deg^2^ to a 4{sigma} sensitivity of >=100mmJy at 1.4GHz, we study the nature of faint radio galaxies. About 50 per cent of the detected radio sources are identified with an optical counterpart revealed by CCD photometry to m_R=22.5mag. Near-infrared (K-band) data are also available for a selected sample of the radio sources, while spectroscopic observations have been carried out for about 40 per cent of the optically identified sample. These provide redshifts and information on the stellar content. Emission-line ratios imply that most of the emission-line sources are star-forming galaxies, with a small contribution (~10 per cent) from Sy1/Sy2 type objects. We also find a significant number of absorption-line systems, likely to be ellipticals. These dominate at high flux densities (>1mJy) but are also found at sub-mJy levels. Using the Balmer decrement we find a visual extinction A_V_=1.0 for the star-forming faint radio sources. This moderate reddening is consistent with the V-R and R-K colours of the optically identified sources. For emission-line galaxies, there is a correlation between the radio power and the Halpha luminosity, in agreement with the result of Benn et al. (1993MNRAS.263....9B). This suggests that the radio emission of starburst radio galaxies is a good indicator of star formation activity.
15644. The Photometric Magnitude Difference Catalog
ID:
ivo://CDS.VizieR/II/235
Title:
The Photometric Magnitude Difference Catalog
Short Name:
II/235
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Photometric Magnitude Difference Catalog is a collection of all double star photometric data which does not contain astrometric information and is therefore inappropriate for the Washington Double Star Catalog. Magnitude difference information can be useful in estimating mass ratios, determining photocentric positions which are color dependent, or into investigations of variability in close binary systems. Due to uncertainties in bandpass characteristics or variability, no summary line is presented, rather a complete listing of all data.
15645. The planet-metallicity correlation.
ID:
ivo://CDS.VizieR/J/ApJ/622/1102
Title:
The planet-metallicity correlation.
Short Name:
J/ApJ/622/1102
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have recently carried out spectral synthesis modeling to determine T_eff_, log(g), vsin(i), and [Fe/H] for 1040 FGK-type stars on the Keck, Lick, and Anglo-Australian Telescope planet search programs. This is the first time that a single, uniform spectroscopic analysis has been made for every star on a large Doppler planet search survey. We identify a subset of 850 stars that have Doppler observations sufficient to detect uniformly all planets with radial velocity semiamplitudes K>30m/s and orbital periods shorter than 4yr.
15646. The PMM USNO-A1.0 Catalogue
ID:
ivo://CDS.VizieR/I/243
Title:
The PMM USNO-A1.0 Catalogue
Short Name:
I/243
Date:
21 Oct 2021
Publisher:
CDS
Description:
USNO-A1.0 is a catalog of 488,006,860 sources whose positions can be used for astrometric references. These sources were detected by the Precision Measuring Machine (PMM) built and operated by the U. S. Naval Observatory Flagstaff Station during the scanning and processing of the Palomar Observatory Sky Survey I (POSS-I) O and E plates, the UK Science Research Council SRC-J survey plates, and the European Southern Observatory ESO-R survey plates. The PMM detects and processes at and beyond the nominal limiting magnitude of these surveys, but the large number of spurious detections requires that a filter be used to eliminate as many as possible. USNO-A's sole inclusion requirement was that there be spatially coincident detections (within a 2 arcsecond radius aperture) on the blue and red survey plate. For field centers of -30 degrees and above, data come from POSS-I plates, while data from field centers of -35 and below come from SRC-J and ESO-R plates.
15647. The population of compact radio sources in ONC
ID:
ivo://CDS.VizieR/J/ApJ/822/93
Title:
The population of compact radio sources in ONC
Short Name:
J/ApJ/822/93
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a deep centimeter-wavelength catalog of the Orion Nebula Cluster (ONC), based on a 30hr single-pointing observation with the Karl G. Jansky Very Large Array in its high-resolution A-configuration using two 1GHz bands centered at 4.7 and 7.3GHz. A total of 556 compact sources were detected in a map with a nominal rms noise of 3{mu}Jy/bm, limited by complex source structure and the primary beam response. Compared to previous catalogs, our detections increase the sample of known compact radio sources in the ONC by more than a factor of seven. The new data show complex emission on a wide range of spatial scales. Following a preliminary correction for the wideband primary-beam response, we determine radio spectral indices for 170 sources whose index uncertainties are less than +/-0.5. We compare the radio to the X-ray and near-infrared point-source populations, noting similarities and differences.
15648. The population of pulsating variable stars in Sextans
ID:
ivo://CDS.VizieR/J/AJ/157/35
Title:
The population of pulsating variable stars in Sextans
Short Name:
J/AJ/157/35
Date:
21 Oct 2021
Publisher:
CDS
Description:
A large extension of the Sextans dwarf spheroidal galaxy, 7 deg^2^, has been surveyed for variable stars using the Dark Energy Camera at the Blanco Telescope at Cerro Tololo Inter-American Observatory, Chile. We report seven anomalous Cepheids, 199 RR Lyrae stars, and 16 dwarf Cepheids in the field. This is only the fifth extragalactic system in which dwarf Cepheids have been systematically searched. Henceforth, the new stars increase the census of stars coming from different environments that can be used to asses the advantages and limitations of using dwarf Cepheids as standard candles in populations for which the metallicity is not necessarily known. The dwarf Cepheids found in Sextans have a mean period of 0.066 day and a mean g amplitude of 0.87 mag. They are located below the horizontal branch, spanning a range of 0.8 mag: 21.9<g<22.7. The number of dwarf Cepheids in Sextans is low compared with other galaxies such as Carina, which has a strong intermediate-age population. On the other hand, the number and ratio of RR Lyrae stars to dwarf Cepheids are quite similar to those of Sculptor, a galaxy which, as Sextans, is dominated by an old stellar population. The dwarf Cepheid stars found in Sextans follow a well-constrained period-luminosity relationship with an rms=0.05 mag in the g band, which was set up by anchoring to the distance modulus given by the RR Lyrae stars. Although the majority of the variable stars in Sextans are located toward the center of the galaxy, we have found two RR Lyrae stars and one anomalous Cepheid in the outskirts of the galaxy that may be extratidal stars and suggest that this galaxy may be undergoing tidal destruction. These possible extratidal variable stars share the same proper motions as Sextans, as seen by recent Gaia measurements. Two additional stars that we initially classified as foreground RR Lyrae stars may actually be other examples of Sextans extratidal anomalous Cepheids, although radial velocities are needed to prove that scenario.
15649. The populations of Carina. II. Abundances
ID:
ivo://CDS.VizieR/J/ApJS/230/28
Title:
The populations of Carina. II. Abundances
Short Name:
J/ApJS/230/28
Date:
21 Oct 2021
Publisher:
CDS
Description:
Chemical abundances are presented for 19 elements in a sample of 63 red giants in the Carina dwarf spheroidal galaxy (dSph), based on homogeneous 1D/LTE model atmosphere analyses of our own observations (32 stars) and data available in the literature (a further 31 independent stars). The (Fe) metallicity and [{alpha}/Fe] distribution functions have mean values and dispersions of -1.59 and 0.33dex ([Fe/H] range: -2.68 to -0.64) and 0.07 and 0.13dex ([{alpha}/Fe] range: -0.27 to 0.25), respectively. We confirm the finding of Venn+ (2012, J/ApJ/751/102) that a small percentage (some 10% in the present investigation) of the sample shows clear evidence for significant enrichment by Type Ia supernova (SN Ia) ejecta. Calcium, with the most accurately determined abundance of the {alpha}-elements, shows an asymmetric distribution toward smaller values of [Ca/Fe] at all [Fe/H], most significantly over -2.0<[Fe/H]<-1.0, suggestive of incomplete mixing of the ejecta of SNe Ia with the ambient medium of each of Carina's generations. Approximate color-magnitude diagram age estimates are presented for the sample, and together with our chemical abundances, compared with the results of our previous synthetic color-magnitude diagram analysis, which reported the details of Carina's four well-defined populations. We searched for the Na-O anticorrelation universally reported in the Galaxy's globular clusters and confirm that this phenomenon does not exist in Carina. We also found that one of the 32 stars in our sample has an extremely enhanced lithium abundance-A(Li)_NLTE_=+3.36, consistent with membership of the ~1% group of Li-rich stars in dSph described by Kirby+ (2012ApJ...752L..16K).
15650. The PPMXL Catalog
ID:
ivo://CDS.VizieR/I/317
Title:
The PPMXL Catalog
Short Name:
I/317
Date:
21 Oct 2021
Publisher:
CDS
Description:
USNO-B1.0 (Cat. I/284) and 2MASS (Cat. II/246) are the most widely used full-sky surveys. However, 2MASS has no proper motions at all, and USNO-B1.0 published only relative, not absolute (i.e. on ICRS) proper motions. We performed a new determination of mean positions and proper motions on the ICRS system by combining USNO-B1.0 and 2MASS astrometry. This catalog is called PPMXL, and it aims to be complete from the brightest stars down to about V=20 full-sky. PPMXL contains about 900 million objects, some 410 million with 2MASS photometry, and is the largest collection of ICRS proper motions at present. As representative for the ICRS we chose PPMX. The recently released UCAC3 (Cat. I/315) could not be used because we found plate-dependent distortions in its proper motion system north of -20{deg} declination. UCAC3 served as an intermediate system for {demta}<-20{deg}. The resulting typical individual mean errors of the proper motions range from 4mas/yr to more than 10mas/yr depending on observational history. The mean errors of positions at epoch 2000.0 are 80 to 120 mas, if 2MASS astrometry could be used, 150 to 300 mas else. We also give correction tables to convert USNO-B1.0 observations of e.g. minor planets to the ICRS system.

Limit your search

more »

more »

more »

more »

more »

more »