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3041. Revised LGGS UBVRI photometry of M31 and M33 stars
ID:
ivo://CDS.VizieR/J/AJ/152/62
Title:
Revised LGGS UBVRI photometry of M31 and M33 stars
Short Name:
J/AJ/152/62
Date:
21 Oct 2021
Publisher:
CDS
Description:
We describe our spectroscopic follow-up to the Local Group Galaxy Survey (LGGS) photometry of M31 and M33. We have obtained new spectroscopy of 1895 stars, allowing us to classify 1496 of them for the first time. Our study has identified many foreground stars, and established membership for hundreds of early- and mid-type supergiants. We have also found nine new candidate luminous blue variables and a previously unrecognized Wolf-Rayet star. We republish the LGGS M31 and M33 catalogs with improved coordinates, and including spectroscopy from the literature and our new results. The spectroscopy in this paper is responsible for the vast majority of the stellar classifications in these two nearby spiral neighbors. The most luminous (and hence massive) of the stars in our sample are early-type B supergiants, as expected; the more massive O stars are more rare and fainter visually, and thus mostly remain unobserved so far. The majority of the unevolved stars in our sample are in the 20-40M_{Sun}_ range.
3042. Revised New General Catalogue
ID:
ivo://CDS.VizieR/VII/1B
Title:
Revised New General Catalogue
Short Name:
VII/1B
Date:
21 Oct 2021
Publisher:
CDS
Description:
The catalog is a modern, revised, and expanded version of the original NGC (Dreyer 1888). In addition to incorporating the many corrections to the NGC found over the years, each object was verified on Palomar Observatory Sky Survey (POSS) prints and on plates for southern objects specifically taken for the purpose (although about 90 southern objects could not be verified). Please refer to the documentation by Wayne H. Warren Jr. in file "adc.doc".
3044. Revised SWIRE photometric redshifts
ID:
ivo://CDS.VizieR/II/326
Title:
Revised SWIRE photometric redshifts
Short Name:
II/326
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have revised the Spitzer Wide-Area Infrared Extragalactic survey (SWIRE) Photometric Redshift Catalogue to take account of new optical photometry in several of the SWIRE areas, and incorporating Two Micron All Sky Survey (2MASS) and UKIRT Infrared Deep Sky Survey (UKIDSS) near-infrared data. Aperture matching is an important issue for combining near-infrared and optical data, and we have explored a number of methods of doing this. The increased number of photometric bands available for the redshift solution results in improvements both in the rms error and, especially, in the outlier rate. We have also found that incorporating the dust torus emission into the quasi-stellar object (QSO) templates improves the performance for QSO redshift estimation. Our revised redshift catalogue contains over 1 million extragalactic objects, of which 26 288 are QSOs.
3045. RGB abundances in the disk, stream & halo of M31
ID:
ivo://CDS.VizieR/J/ApJ/889/177
Title:
RGB abundances in the disk, stream & halo of M31
Short Name:
J/ApJ/889/177
Date:
21 Oct 2021
Publisher:
CDS
Description:
We measured [Fe/H] and [{alpha}/Fe] using spectral synthesis of low-resolution stellar spectroscopy for 70 individual red-giant-branch stars across four fields spanning the outer disk, Giant Stellar Stream (GSS), and inner halo of M31. Fields at M31-centric projected distances of 23kpc in the halo, 12kpc in the halo, 22kpc in the GSS, and 26kpc in the outer disk are {alpha}-enhanced, with <[{alpha}/Fe]>=0.43, 0.50, 0.41, and 0.58, respectively. The 23 and 12kpc halo fields are relatively metal-poor, with <[Fe/H]>=-1.54 and -1.30, whereas the 22kpc GSS and 26kpc outer disk fields are relatively metal-rich with <[Fe/H]>=-0.84 and -0.92, respectively. For fields with substructure, we separated the stellar populations into kinematically hot stellar halo components and kinematically cold components. We did not find any evidence of a radial [{alpha}/Fe] gradient along the high surface brightness core of the GSS between ~17 and 22kpc. However, we found tentative suggestions of a negative radial [{alpha}/Fe] gradient in the stellar halo, which may indicate that different progenitor(s) or formation mechanisms contributed to the build up of the inner versus outer halo. Additionally, the [{alpha}/Fe] distribution of the metal-rich ([Fe/H]>-1.5), smooth inner stellar halo (r_proj_<~26kpc) is inconsistent with having formed from the disruption of a progenitor(s) similar to present-day M31 satellite galaxies. The 26kpc outer disk is most likely associated with the extended disk of M31, where its high {alpha}-enhancement provides support for an episode of rapid star formation in M31's disk possibly induced by a major merger.
3046. RGB sample of BL Lacertae objects
ID:
ivo://CDS.VizieR/J/ApJ/525/127
Title:
RGB sample of BL Lacertae objects
Short Name:
J/ApJ/525/127
Date:
21 Oct 2021
Publisher:
CDS
Description:
Combining newly identified and previously known BL Lacertae objects from the ROSAT All-Sky Survey-Green Bank (RGB) catalog, we present a sample of 127 BL Lacertae objects, the largest ever derived from a single uniform survey. A complete sample of 33 objects brighter than O=18.0 mag is also presented. These samples are compared to other known BL Lac samples and are generally found to exhibit properties intermediate between those of the previously disparate classes of high- and low-energy-peaked BL Lacertae objects (HBLs and LBLs, respectively). This result is most dramatic in the distribution of the X-ray to radio logarithmic flux ratios, where the RGB BL Lacertae objects are shown to peak precisely where the sharp dichotomy between the two subclasses was previously seen.
3047. RGB stars in NGC 6822, Ca II triplet
ID:
ivo://CDS.VizieR/J/MNRAS/456/4315
Title:
RGB stars in NGC 6822, Ca II triplet
Short Name:
J/MNRAS/456/4315
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a detailed analysis of the chemistry and kinematics of red giants in the dwarf irregular galaxy NGC 6822. Spectroscopy at ~8500{AA} was acquired for 72 red giant stars across two fields using FORS2 at the VLT. Line-of-sight extinction was individually estimated for each target star to accommodate the variable reddening across NGC 6822. The mean radial velocity was found to be <v_rad_>=-52.8+/-2.2km/s with dispersion {sigma}_v_=24.1km/s, in agreement with other studies. Ca ii triplet equivalent widths were converted into [Fe/H] metallicities using a V magnitude proxy for surface gravity. The average metallicity was <[Fe/H]>=-0.84+/-0.04 with dispersion {sigma}=0.31dex and interquartile range 0.48. Our assignment of individual reddening values makes our analysis more sensitive to spatial variations in metallicity than previous studies. We divide our sample into metal-rich and metal-poor stars; the former were found to cluster towards small radii with the metal-poor stars more evenly distributed across the galaxy. The velocity dispersion of the metal-poor stars was found to be higher than that of the metal-rich stars {sigma}_vMP_=27.4km/s; {sigma}_vMR_=21.1km/s); combined with the age-metallicity relation this indicates that the older populations have either been dynamically heated during their lifetimes or were born in a less disc-like distribution than the younger stars.. The low ratio v_rot_/{sigma}_v_ suggests that within the inner 10-arcmin, NGC 6822's stars are dynamically decoupled from the HI gas, and possibly distributed in a thick disc or spheroid structure.
3048. RGB stars in Sagittarius streams
ID:
ivo://CDS.VizieR/J/A+A/464/201
Title:
RGB stars in Sagittarius streams
Short Name:
J/A+A/464/201
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Sagittarius (Sgr) dwarf spheroidal galaxy is currently being disrupted under the strain of the Milky Way. A reliable reconstruction of Sgr star formation history can only be obtained by combining core and stream information. We present radial velocities for 67 stars belonging to the Sgr Stream. For 12 stars in the sample we also present iron (Fe) and {alpha}-element (Mg, Ca) abundances.
3049. RGZ: distortion of radio galaxies by galaxy clusters
ID:
ivo://CDS.VizieR/J/AJ/157/126
Title:
RGZ: distortion of radio galaxies by galaxy clusters
Short Name:
J/AJ/157/126
Date:
21 Oct 2021
Publisher:
CDS
Description:
We study the impact of cluster environment on the morphology of a sample of 4304 extended radio galaxies from Radio Galaxy Zoo. A total of 87% of the sample lies within a projected 15 Mpc of an optically identified cluster. Brightest cluster galaxies (BCGs) are more likely than other cluster members to be radio sources, and are also moderately bent. The surface density as a function of separation from cluster center of non-BCG radio galaxies follows a power law with index -1.10+/-0.03 out to 10 r_500_ (~7 Mpc), which is steeper than the corresponding distribution for optically selected galaxies. Non-BCG radio galaxies are statistically more bent the closer they are to the cluster center. Within the inner 1.5 r_500_ (~1 Mpc) of a cluster, non-BCG radio galaxies are statistically more bent in high-mass clusters than in low-mass clusters. Together, we find that non-BCG sources are statistically more bent in environments that exert greater ram pressure. We use the orientation of bent radio galaxies as an indicator of galaxy orbits and find that they are preferentially in radial orbits. Away from clusters, there is a large population of bent radio galaxies, limiting their use as cluster locators; however, they are still located within statistically overdense regions. We investigate the asymmetry in the tail length of sources that have their tails aligned along the radius vector from the cluster center, and find that the length of the inward-pointing tail is weakly suppressed for sources close to the center of the cluster.
3050. Rich clusters from SDSS DR8
ID:
ivo://CDS.VizieR/J/A+A/542/A36
Title:
Rich clusters from SDSS DR8
Short Name:
J/A+A/542/A36
Date:
21 Oct 2021
Publisher:
CDS
Description:
The study of the properties of galaxy clusters and their environment gives us information about the formation and evolution of galaxies, groups and clusters, and larger structures - superclusters of galaxies and the whole cosmic web. We study the relations between the multimodality of galaxy clusters drawn from the SDSS DR8 and the environment where they reside. As cluster environment we consider the global luminosity density field, supercluster membership, and supercluster morphology.