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641. AGESVC1 282 deep optical image
ID:
ivo://CDS.VizieR/J/A+A/642/L10
Title:
AGESVC1 282 deep optical image
Short Name:
J/A+A/642/L10
Date:
21 Oct 2021
Publisher:
CDS
Description:
The blind HI survey Arecibo Galaxy Environment Survey (AGES) detected several unresolved sources in the Virgo cluster, which do not have optical counterparts in the Sloan Digital Sky Survey. The origin of these dark clouds is unknown. They might be crucial objects since they could be the so-called dark galaxies, that is, the dark matter halos without stellar content that are expected from cosmological simulations. In order to reveal the nature of the dark clouds, we took a deep optical image of one them, AGESVC1 282, with the newly-commissioned 1.4m Milankovic Telescope. After observing it for 10.4h in the L-filter, the image reached a surface-brightness limit of about 29.1mag/arcsec^+2^ in V. No optical counterpart was detected. We placed an upper limit on the Vband luminosity of the object of 1.1x10^7^L_{sun}_, giving a stellar mass below 1.4x10^7^M_{sun}_ and a HI-to-stellar mass ratio above 3.1. By inspecting archival HI observations of the surrounding region, we found that none of the standard explanations for optically dark HI clouds fits the available constraints on this object.
642. Age & [Z/H] relations of SDSS star-forming galaxies
ID:
ivo://CDS.VizieR/J/ApJ/898/62
Title:
Age & [Z/H] relations of SDSS star-forming galaxies
Short Name:
J/ApJ/898/62
Date:
13 Dec 2021 08:21:08
Publisher:
CDS
Description:
Stellar population parameters correlate with a range of galaxy properties, but it is unclear which relations are causal and which are the result of another underlying trend. In this series, we quantitatively compare trends between stellar population properties and galaxy structural parameters in order to determine which relations are intrinsically tighter, and are therefore more likely to reflect a causal relation. Specifically, we focus on the galaxy structural parameters of mass M, gravitational potential {Phi}~M/R_e_, and surface mass density {Sigma}~M/R_e_^2^. In Barone+ (Paper I; 2018ApJ...856...64B) we found that for early-type galaxies (ETGs) the age-{Sigma} and [Z/H]-{Phi} relations show the least intrinsic scatter as well as the least residual trend with galaxy size. In this work we study the ages and metallicities measured from full spectral fitting of 2085 star-forming galaxies (SFGs) from the SDSS Legacy Survey, selected so all galaxies in the sample are probed to one effective radius. As with the trends found in ETGs, we find that in SFGs age correlates best with stellar surface mass density, and [Z/H] correlates best with gravitational potential. We discuss multiple mechanisms that could lead to these scaling relations. For the [Z/H]-{Phi} relation we conclude that gravitational potential is the primary regulator of metallicity, via its relation to the gas escape velocity. The age-{Sigma} relation is consistent with compact galaxies forming earlier, as higher gas fractions in the early universe cause old galaxies to form more compactly during their in situ formation phase, and may be reinforced by compactness-related quenching mechanisms.
643. Agglomerate of early-type Hipparcos stars
ID:
ivo://CDS.VizieR/J/AN/329/801
Title:
Agglomerate of early-type Hipparcos stars
Short Name:
J/AN/329/801
Date:
21 Oct 2021
Publisher:
CDS
Description:
We study the spatial structure and sub-structure of regions rich in Hipparcos stars with blue BT-VT colours. These regions, which comprise large stellar complexes, OB associations, and young open clusters, are tracers of on-going star formation in the Galaxy. The DBSCAN (Density-Based Spatial Clustering of Applications with Noise) data clustering algorithm is used to look for spatial overdensities of early-type stars. Once an overdensity, "agglomerate", is identified, we carry out a data and bibliographic compilation of their star member candidates. The actual membership in agglomerate of each early-type star is studied based on its heliocentric distance, proper motion, and previous spectro-photometric information. We identify 35 agglomerates of early-type Hipparcos stars. Most of them are associated to previously known clusters and OB associations. The previously unknown P Puppis agglomerate is subject of a dedicated study with Virtual Observatory tools.
644. A 6.7GHz methanol maser survey. II. |b|<2{deg}
ID:
ivo://CDS.VizieR/J/ApJS/241/18
Title:
A 6.7GHz methanol maser survey. II. |b|<2{deg}
Short Name:
J/ApJS/241/18
Date:
21 Oct 2021
Publisher:
CDS
Description:
We report the results of our systematic survey for Galactic 6.7GHz Class II CH_3_OH maser emission toward a sample of young stellar objects. The survey was conducted with the Shanghai Tianma Radio Telescope (TMRT). The sample consists of 3348 sources selected from the all-sky Wide-field Infrared Survey Explorer (WISE) point-source catalog. We discussed the selection criteria in detail and the detection results of those at high Galactic latitudes (i.e., |b|>2{deg}) in a previous paper (Paper I; Yang+ 2017, J/ApJ/846/160). Here, we present the results from the survey of those at low Galactic latitudes, i.e., |b|<2{deg}. Of 1875 selected WISE point sources, 291 positions that were actually associated with 224 sources that were detected with CH_3_OH maser emission. Among them, 32 are newly detected. A majority of the newly detected sources are associated with bright WISE sources. The majority of the detected sources (209/224=93.3%) are quite close to the Galactic Plane (|b|<1{deg}) and lie on the inner spiral arms with positive local standard of rest velocities. The detection rate and the color-color distribution of our detection are all matched with our anticipation. Combining with detections from previous surveys, we compile a catalog of 1085 sources with 6.7GHz CH_3_OH maser emission in our Galaxy.
645. A 4-6GHz RRL survey in the Milky Way
ID:
ivo://CDS.VizieR/J/ApJS/248/3
Title:
A 4-6GHz RRL survey in the Milky Way
Short Name:
J/ApJS/248/3
Date:
21 Oct 2021
Publisher:
CDS
Description:
We performed a radio recombination line (RRL) survey to construct a high-mass star-forming region (HMSFR) sample in the Milky Way based on the all-sky Wide-Field Infrared Survey Explorer point-source catalog. The survey was observed with the Shanghai 65m Tianma radio telescope covering 10 hydrogen RRL transitions ranging from H98{alpha} to H113{alpha} (corresponding to the rest frequencies of 4.5-6.9GHz) simultaneously. Out of 3348 selected targets, we identified an HMSFR sample consisting of 517 sources traced by RRLs; a large fraction of this sample (486) is located near the Galactic Plane (|b|<2{deg}). In addition to the hydrogen RRLs, we also detected helium and carbon RRLs toward 49 and 23 sources, respectively. We crossmatch the RRL detections with the 6.7 methanol maser sources built up in previous works for the same target sample. As a result, 103 HMSFR sources were found to harbor both emissions. In this paper, we present the HMSFR catalog accompanied by the measured RRL line properties and a correlation with our methanol maser sample, which is believed to trace massive stars at earlier stages. The construction of an HMSFR sample consisting of sources in various evolutionary stages indicated by different tracers is fundamental for future studies of high-mass star formation in such regions.
646. A 95 GHz Survey of Methanol Masers
ID:
ivo://CDS.VizieR/J/AZh/72/22
Title:
A 95 GHz Survey of Methanol Masers
Short Name:
J/AZh/72/22
Date:
21 Oct 2021
Publisher:
CDS
Description:
A 95GHz survey of methanol emission in the 8_0_-7_1_A^+^ transition was conducted with the 20-m radio telescope at Onsala. Twenty-six new sources were detected in the emission line. At least nine out of the 35 studied sources are masers.
647. A 5-GHz Survey of Radio Sources
ID:
ivo://CDS.VizieR/J/A+AS/65/267
Title:
A 5-GHz Survey of Radio Sources
Short Name:
J/A+AS/65/267
Date:
21 Oct 2021
Publisher:
CDS
Description:
The results of a sensitive radio survey of about 0.04 sr of extragalactic sky in a narrow strip about declination = +33 deg are reported. The measurements were made with the NRAO 91-meter Green Bank telescope at a frequency of 4760 MHz. A catalogue of the 882 sources detected above a flux density of 15 mJy is given. The area surveyed is part of that covered earlier by the NRAO 5-GHz Survey of Faint Sources, Davis (1971). The results will allow an unbiased study of the variability characteristics of sources common to both surveys.
648. A 5-GHz VLA Survey of the Galactic Plane
ID:
ivo://CDS.VizieR/J/ApJS/91/347
Title:
A 5-GHz VLA Survey of the Galactic Plane
Short Name:
J/ApJS/91/347
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have used the VLA to survey the inner Galaxy (|b|<0.4{deg}, l=350-40{deg}) at 5GHz to a limiting sensitivity of between 2.5 and 10mJy. The survey has resulted in a catalog of 1272 discrete sources (including 100 sources outside the formal survey area) of which we have tentatively identified ~450 as ultracompact H II regions and ~45 as planetary nebulae. Approximately 30% of the radio sources are detected in the IRAS Point Source Catalog. The results confirm a scale height of only 30pc for ultracompact H II regions. We show that source lists generated from the IRAS Point Source Catalog alone suffer serious effects; the combination of the IRAS and radio surveys allows us to produce a much more complete census of the regions of massive star formation in our Galaxy.
649. AGILE bright gamma-ray sources updated list
ID:
ivo://CDS.VizieR/J/A+A/558/A137
Title:
AGILE bright gamma-ray sources updated list
Short Name:
J/A+A/558/A137
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a variability study of a sample of bright {gamma}-ray (30MeV-50GeV ) sources. This sample is an extension of the first AGILE catalogue of -ray sources (1AGL), obtained using the complete set of AGILE observations in pointing mode performed during a 2.3 year period from July 9, 2007 until October 30, 2009. The dataset of AGILE pointed observations covers a long time interval and its {gamma}-ray data archive is useful for monitoring studies of medium-to-high brightness {gamma}-ray sources. In the analysis reported here, we used data obtained with an improved event filter that covers a wider field of view, on a much larger (about 27.5 months) dataset, integrating data on observation block time scales, which mostly range from a few days to thirty days. The data processing resulted in a better characterized source list than 1AGL was, and includes 54 sources, 7 of which are new high galactic latitude (|BII|>=5) sources, 8 are new sources on the galactic plane, and 20 sources from the previous catalogue with revised positions. Eight 1AGL sources (2 high-latitude and 6 on the galactic plane) were not detected in the final processing either because of low Observing Block (OB) exposure and/or due to their position in complex galactic regions. We report the results in a catalogue of all the detections obtained in each single OB, including the variability results for each of these sources. In particular, we found that 12 sources out of 42 or 11 out of 53 are variable, depending on the variability index used, where 42 and 53 are the number of sources for which these indices could be calculated. Seven of the 11 variable sources are blazars, the others are Crab pulsar+nebula, LS I +61 303, Cyg X-3, and 1AGLR J2021+4030.
650. AGILE Mini-Calorimeter {gamma}-ray burst catalog
ID:
ivo://CDS.VizieR/J/A+A/553/A33
Title:
AGILE Mini-Calorimeter {gamma}-ray burst catalog
Short Name:
J/A+A/553/A33
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Mini-Calorimeter of the AGILE satellite can observe the high-energy part of gamma-ray bursts with good timing capability. We present the data of the 85 hard gamma-ray bursts observed by the Mini-Calorimeter since the launch (April 2007) until October 2009. We report the timing data for 84 and spectral data for 21 bursts.

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