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2401. CCD UBVRI photometry of 3 open clusters
ID:
ivo://CDS.VizieR/J/other/BASI/32.295
Title:
CCD UBVRI photometry of 3 open clusters
Short Name:
J/other/BASI/32.
Date:
21 Oct 2021
Publisher:
CDS
Description:
CCD photometric observations of three open clusters Berkeley 15 (= OCl 414), Czernik 18 (= OCl 426) and NGC 2401 (= OCl 588), obtained for the first time in UBVRI filters down to V=20mag, are presented here. They are located at distances of 1259, 955 and 3467 parsecs with their respective ages estimated as ~5x10^9^years, ~0.8 to 1x10^9^years and ~1x10^9^years. While OCl 414 and OCl 426 are in the direction of the Auriga - Perseus constellations, OCl 588 is placed in the direction of Ophiuchus constellation in our Galaxy. The clusters studied here are of intermediate and old age category.
2402. CCD UBVRI photometry of 7 open star clusters
ID:
ivo://CDS.VizieR/J/MNRAS/327/23
Title:
CCD UBVRI photometry of 7 open star clusters
Short Name:
J/MNRAS/327/23
Date:
21 Oct 2021
Publisher:
CDS
Description:
We derive cluster parameters and mass functions from new UBVRI CCD photometric observations of ~3500 stars reaching down to V~20mag for the distant southern open star clusters NGC 3105, NGC 3603, Melotte 105, Hogg 15, NGC 4815, Pismis 20 and NGC 6253. For NGC 3105 and Hogg 15, CCD data are presented for the first time. The observations were carried out in 1992 between February 28 and March 8, June 5 and 9, and July 9 and 12 in the Cousins U, B, V, R and I photometric bands using CCD detector at the 1.0-m Elizabeth Telescope at the South African Astronomical Observatory (SAAO), Sutherland.
2403. CCD Vilnius photometry of M56
ID:
ivo://CDS.VizieR/J/A+A/388/149
Title:
CCD Vilnius photometry of M56
Short Name:
J/A+A/388/149
Date:
21 Oct 2021
Publisher:
CDS
Description:
CCD observations of field stars in an area north-east of the globular cluster M 56 were obtained in six bands of the Vilnius photometric system. The data sets cover a field of 9'x9.5'. An outline of the data pathway from observations to reduction via IRAF is outlined in this text. Photometry of 366 stars brighter than 18th V magnitude has been obtained and the analysis of the observational errors is discussed.
2404. CCD Washington CT1T2 photometry of stars in LMC
ID:
ivo://CDS.VizieR/J/AJ/144/100
Title:
CCD Washington CT1T2 photometry of stars in LMC
Short Name:
J/AJ/144/100
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present photometry for an unprecedented database of some 5.5million stars distributed throughout the Large Magellanic Cloud main body, from 21 fields covering a total area of 7.6deg^2^, obtained from Washington CT_1_T_2_ CTIO 4m MOSAIC data. Extensive artificial star tests over the whole mosaic image data set and the observed behavior of the photometric errors with magnitude demonstrate the accuracy of the morphology and clearly delineate the position of the main features in the color-magnitude diagrams (CMDs). The representative T_1_(MS TO) mags are on average ~0.5mag brighter than the T_1_ mags for the 100% completeness level of the respective field, allowing us to derive an accurate age estimate. We have analyzed the CMD Hess diagrams and used the peaks in star counts at the main sequence turnoff and red clump (RC) locations to age date the most dominant sub-population (or "representative" population) in the stellar population mix. The metallicity of this representative population is estimated from the locus of the most populous red giant branch track. We use these results to derive age and metallicity estimates for all of our fields. The analyzed fields span age and metallicity ranges covering most of the galaxy's lifetime and chemical enrichment, i.e., ages and metallicities between ~1 and 13Gyr and ~-0.2 and -1.2dex, respectively. We show that the dispersions associated with the mean ages and metallicities represent in general a satisfactory estimate of the age/metallicity spread (~1-3 Gyr/0.2-0.3 dex), although a few subfields have a slightly larger age/metallicity spread. Finally, we revisit the study of the vertical structure (VS) phenomenon, a striking feature composed of stars that extend from the bottom, bluest end of the RC to ~0.45mag fainter. We confirm that the VS phenomenon is not clearly seen in most of the studied fields and suggest that its occurrence is linked to some other condition(s) in addition to the appropriate age, metallicity, and the necessary red giant star density.
2405. CCD Washington photometry of Antlia cluster
ID:
ivo://CDS.VizieR/J/MNRAS/497/1791
Title:
CCD Washington photometry of Antlia cluster
Short Name:
J/MNRAS/497/1791
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present an extension of our previous research on the early-type galaxy population of the Antlia cluster (d~35Mpc), achieving a total coverage of ~2.6deg^2^ and performing surface photometry for ~300 galaxies, 130 of which are new uncatalogued ones. Such new galaxies mainly fall in the low surface brightness (LSB) regime, but there are also some lenticulars (S0) which support the existence of unique functions that connect bright and dwarf galaxies in the scaling relations. We analyse the projected spatial distribution of galaxies up to a distance of ~800kpc from NGC 3268, the adopted centre, as well as the radial velocity distribution and the correlation between galaxy colour and effective radius with the projected spatial distribution. We also obtain the luminosity function of the early-type galaxies and the distribution of stellar masses using the T1-band magnitudes and adopted mass-luminosity ratios. Additionally, we correlate the central galaxy distribution with an X-ray emission map from the literature. Based on the analysis of the radial velocities and galaxy colour distributions, we find that galaxies redder than the colour-magnitude relation (CMR) have a velocity distribution strongly concentrated towards the values of the dominant galaxies and are homogeneously distributed throughout the cluster. Those bluer than the CMR, in turn, have a much more extended radial velocity distribution and are concentrated towards the centre of the cluster. We also identify 12 candidates to ultra diffuse galaxies (UDG), that seem to be split into two families, and speculate about their origins in the context of the cluster structure.
2406. Cchemical abundances of 6 open cluster stars
ID:
ivo://CDS.VizieR/J/A+A/643/A12
Title:
Cchemical abundances of 6 open cluster stars
Short Name:
J/A+A/643/A12
Date:
21 Oct 2021
Publisher:
CDS
Description:
Open clusters are excellent tracers of the chemical evolution of the Galactic disc. The spatial distribution of their elemental abundances, through the analysis of high-quality and high-resolution spectra, provides insight into the chemical evolution and mechanisms of element nucleosynthesis in regions characterised by different conditions (e.g. star formation efficiency and metallicity). In the framework of the Stellar Population Astrophysics (SPA) project, we present new observations and spectral analysis of four sparsely studied open clusters located in the solar neighbourhood, namely Collinder 350, Gulliver 51, NGC 7044, and Ruprecht 171. We exploit the HARPS-N spectrograph at the TNG telescope to acquire high-resolution optical spectra for 15 member stars of four clusters. We derive stellar parameters (Teff, logg, [Fe/H] and {xi) using both the equivalent width (EW) analysis and the spectral fitting technique. We compute elemental abundances for light, {alpha}-, iron-peak, and n-capture elements using the EW measurement approach. We investigate the origin of the correlation between metallicity and stellar parameters derived with the EW method for the coolest stars of the sample (Teff<4300K). The correlation is likely due to the challenging continuum setting and to a general inaccuracy of model atmospheres used to reproduce the conditions of very cool giant stars. We locate the properties of our clusters in the radial distributions of metallicity and abundance ratios, comparing our results with clusters from the Gaia-ESO and APOGEE surveys. We present the [X/Fe]-[Fe/H] and [X/Fe]-RGC trends for elements in common between the two surveys. Finally, we derive the C and Li abundances as a function of the evolutionary phase and compare them with theoretical models. The SPA survey, with its high-resolution spectra, allows us to fully characterise the chemistry of nearby clusters. With a single set of spectra, we provide chemical abundances for a variety of chemical elements, which are comparable to those obtained in two of the largest surveys combined. The metallicities and abundance ratios of our clusters fit very well in the radial distributions defined by the recent literature, reinforcing the importance of star clusters to outline the spatial distribution of abundances in our Galaxy. Moreover, the abundances of C and Li, modified by stellar evolution during the giant phase, agree with evolutionary prescriptions (rotation-induced mixing) for their masses and metallicities.
2407. [CCJ2015b] HZ4 [CII] 158um datacube
ID:
ivo://CDS.VizieR/J/A+A/649/A31
Title:
[CCJ2015b] HZ4 [CII] 158um datacube
Short Name:
J/A+A/649/A31
Date:
22 Feb 2022
Publisher:
CDS
Description:
We present new Atacama Large Millimeter/Submillimeter Array (ALMA) observations of the [CII] 158um transition and the dust continuum in HZ4, a typical star-forming galaxy when the Universe was only ~1Gyr old (z~5.5). Our high ~0.3" spatial resolution allows us to study the relationships between [CII] line emission, star formation rate, and far-infrared emission on spatial scales of ~2kpc. In the central ~4kpc of HZ4 the [CII]/FIR is ~3x10^-3^ on global scales as well as on spatially resolved scales of ~2kpc, comparable to the ratio observed in local moderate starburst galaxies such as M82 or M83. For the first time in an individual normal galaxy at this redshift, we find evidence for outflowing gas from the central star-forming region in the direction of the minor axis of the galaxy. The projected velocity of the outflow is ~400km/s, and the neutral gas-mass outflow rate is ~3-6 times higher than the star formation rate in the central region. Finally, we detect a diffuse component of [CII] emission, or [CII] halo, that extends beyond the star-forming disk and has a diameter of ~12kpc. The outflow, which has a velocity approximately half of the escape velocity of the system, most likely partly fuels the [CII] extended emission. Together with the kinematic analysis of HZ4 (presented in a forthcoming paper), the analysis supports the hypothesis that HZ4 is a typical star-forming disk at z~5 with interstellar medium conditions similar to present-day galaxies forming stars at a similar level, driving a galactic outflow that may already play a role in its evolution.
2408. 3C 236 CO maps
ID:
ivo://CDS.VizieR/J/A+A/549/A58
Title:
3C 236 CO maps
Short Name:
J/A+A/549/A58
Date:
21 Oct 2021
Publisher:
CDS
Description:
There is growing observational evidence of active galactic nuclei (AGN) feedback on the ISM of radio-quiet and radio-loud galaxies. While AGN feedback is expected to be more common at high redshift objects, the study of local universe galaxies help to better characterize the different manifestations of AGN feedback.AIMS. Molecular line observations can be used to quantify the mass and energy budget of the gas affected by AGN feedback. We study the emission of molecular gas in 3C 236, a Faranoff-Riley type 2 (FR II) radio source at z~0.1, and search for the footprints of AGN feedback. 3C 236 shows signs of a reactivation of its AGN triggered by a recent minor merger episode. Observations have also previously identified an extreme HI outflow in this source. The IRAM Plateau de Bure interferometer (PdBI) has been used to study the distribution and kinematics of molecular gas in 3C 236 by imaging with high spatial resolution (0.6") the emission of the 2-1 line of ^12^CO in the nucleus of the galaxy. We have searched for outflow signatures in the CO map. We have also derived the star-formation rate (SFR) in 3C 236 using data available from the literature at UV, optical and IR wavelengths, to determine the star-formation efficiency of molecular gas. The CO emission in 3C 236 comes from a spatially resolved ~1.4" (2.6kpc)-diameter disk characterized by a regular rotating pattern. Within the limits imposed by the sensitivity and velocity coverage of the CO data, we do not detect any outflow signatures in the cold molecular gas. The disk has a cold gas mass M(H_2_)~2.1x10^9^M_{sun}_. Based on CO we determine a new value for the redshift of the source z_CO_=0.09927+/-0.0002. The similarity between the CO and HI profiles indicates that the deep HI absorption in 3C 236 can be accounted for by a rotating HI structure. This restricts the evidence of HI outflow only to the most extreme velocities. In the light of the new redshift value, the analysis of the ionized gas kinematics reveals a fast (~1000km/s) outflow. As for the CO emitting gas, outflow signatures are nevertheless absent in the warm molecular gas emission traced by infrared H_2_ lines. The star-formation efficiency in 3C 236 is consistent with the value measured in normal galaxies, which follow the canonical Kennicutt-Schmidt (KS) relation. This result, confirmed to hold in other young radio sources examined in this work, is in stark contrast with the factor of 10-50 lower SFE that has been claimed to characterize evolved powerful radio galaxies. There are no signs of ongoing AGN feedback on the molecular ISM of 3C 236. The recent reactivation of the AGN in 3C 236 (about ~10^5^yr ago) is a likely explanation for the early evolutionary status of its molecular disk.
2409. Ccompact group galaxies UV and IR SFR
ID:
ivo://CDS.VizieR/J/MNRAS/459/2948
Title:
Ccompact group galaxies UV and IR SFR
Short Name:
J/MNRAS/459/2948
Date:
21 Oct 2021
Publisher:
CDS
Description:
Compact groups of galaxies provide insight into the role of low-mass, dense environments in galaxy evolution because the low velocity dispersions and close proximity of galaxy members result in frequent interactions that take place over extended time-scales. We expand the census of star formation in compact group galaxies by Tzanavaris et al. (2010, Cat. J/ApJS/212/9) and collaborators with Swift UVOT, Spitzer IRAC and MIPS 24{mu}m photometry of a sample of 183 galaxies in 46 compact groups. After correcting luminosities for the contribution from old stellar populations, we estimate the dust-unobscured star formation rate (SFR_UV_) using the UVOT uvw2 photometry. Similarly, we use the MIPS 24 {mu}m photometry to estimate the component of the SFR that is obscured by dust (SFR_IR_). We find that galaxies which are MIR-active (MIR-'red'), also have bluer UV colours, higher specific SFRs, and tend to lie in HI-rich groups, while galaxies that are MIR-inactive (MIR-'blue') have redder UV colours, lower specific SFRs, and tend to lie in HI-poor groups. We find the SFRs to be continuously distributed with a peak at about 1M_{sun}_/yr, indicating this might be the most common value in compact groups. In contrast, the specific SFR distribution is bimodal, and there is a clear distinction between star-forming and quiescent galaxies. Overall, our results suggest that the specific SFR is the best tracer of gas depletion and galaxy evolution in compact groups.
2410. 10C cont.: a deeper radio survey at 15.7GHz
ID:
ivo://CDS.VizieR/J/MNRAS/457/1496
Title:
10C cont.: a deeper radio survey at 15.7GHz
Short Name:
J/MNRAS/457/1496
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present deep 15.7-GHz observations made with the Arcminute Microkelvin Imager (AMI) Large Array in two fields previously observed as part of the Tenth Cambridge (10C) survey. These observations allow the source counts to be calculated down to 0.1mJy, a factor of five deeper than achieved by the 10C survey. The new source counts are consistent with the extrapolated fit to the 10C source count, and display no evidence for either steepening or flattening of the counts. There is thus no evidence for the emergence of a significant new population of sources (e.g. starforming) at 15.7GHz flux densities above 0.1mJy, the flux density level at which we expect starforming galaxies to begin to contribute. Comparisons with the de Zotti et al. model and the SKADS Simulated Sky show that they both underestimate the observed number of sources by a factor of two at this flux density level. We suggest that this is due to the flat-spectrum cores of radio galaxies contributing more significantly to the counts than predicted by the models.

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