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3301. Cordoba Carte du Ciel-Astrographic Catalog, CCAC
ID:
ivo://CDS.VizieR/J/A+A/521/A39
Title:
Cordoba Carte du Ciel-Astrographic Catalog, CCAC
Short Name:
J/A+A/521/A39
Date:
21 Oct 2021
Publisher:
CDS
Description:
Based on stellar positions and proper motions, we aim to re-analyse the region of the controversial open cluster Collinder 132. Methods. We have developed a model which analyse the proper motion distribution and the stellar density to find moving groups. The astrometric data was obtained from four Carte du Ciel (CdC) and one Astrogaphic Catalogue (AC) plates of the Cordoba Astronomical Observatory collection (Argentina). We detected an open cluster from the field stars and calculated the mean proper motion and the membership probabilities of the stars of the region. We report new coordinates of its centre RAc=108.347deg, DEc=-31.011deg, the components of mean proper motion mu_RA_cosDE=-2.62+/-0.44mas/yr, mu_DE_=4.79+/-0.88mas/yr. 11 stars are astrometric members giving a value of 370 for the cluster angular diameter. 6 stars fullfill astrometric and photometric analysis for being cluster members and locate the cluster at 360pc from the Sun. An over-density in the VPD was found after removing the cluster members, consequently a simple model for the proper motion distribution of an association and of the field was adopted. We report the components of the association mean proper motion mu_RA_cosDE=-1.38+/-0.14mas/yr, mu_DE_=2.26+/-0.16mas/yr. 174 astrometric members were found while 11 members have been located between 417 and 660pc from the Sun by Tycho-2 photometry.
3302. Cordoba Durchmusterung
ID:
ivo://CDS.VizieR/I/114
Title:
Cordoba Durchmusterung
Short Name:
I/114
Date:
21 Oct 2021
Publisher:
CDS
Description:
The "Cordoba Durchmusterung" (CD, Thome 1892-1932) is a visual survey of southern stars in the declination zones -22 to -89 deg, carried out as an extension to the "Bonner Durchmusterung" (BD) catalogs of Argelander (1859-1862) (see also Kuestner 1903) and Schoenfeld (1886). It contains 613959 records for stars brighter than 10.0 magnitude.
3303. Core-collapse SNe and host galaxies
ID:
ivo://CDS.VizieR/J/ApJ/759/107
Title:
Core-collapse SNe and host galaxies
Short Name:
J/ApJ/759/107
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have used images and spectra of the Sloan Digital Sky Survey to examine the host galaxies of 519 nearby supernovae (SN). The colors at the sites of the explosions, as well as chemical abundances, and specific star formation rates (SFRs) of the host galaxies provide circumstantial evidence on the origin of each SN type. We examine separately SN II, SN IIn, SN IIb, SN Ib, SN Ic, and SN Ic with broad lines (SN Ic-BL). For host galaxies that have multiple spectroscopic fibers, we select the fiber with host radial offset most similar to that of the SN. Type Ic SN explode at small host offsets, and their hosts have exceptionally strongly star-forming, metal-rich, and dusty stellar populations near their centers. The SN Ic-BL and SN IIb explode in exceptionally blue locations, and, in our sample, we find that the host spectra for SN Ic-BL show lower average oxygen abundances than those for SN Ic. SN IIb host fiber spectra are also more metal-poor than those for SN Ib, although a significant difference exists for only one of two strong-line diagnostics. SN Ic-BL host galaxy emission lines show strong central specific SFRs. In contrast, we find no strong evidence for different environments for SN IIn compared to the sites of SN II. Because our SN sample is constructed from a variety of sources, there is always a risk that sampling methods can produce misleading results. We have separated the SN discovered by targeted surveys from those discovered by galaxy-impartial searches to examine these questions and show that our results do not depend sensitively on the discovery technique.
3304. Core collapse supernovae (type Ibc)
ID:
ivo://CDS.VizieR/J/MNRAS/436/774
Title:
Core collapse supernovae (type Ibc)
Short Name:
J/MNRAS/436/774
Date:
21 Oct 2021
Publisher:
CDS
Description:
The progenitors of many Type II core-collapse supernovae (SNe) have now been identified directly on pre-discovery imaging. Here, we present an extensive search for the progenitors of Type Ibc SNe in all available pre-discovery imaging since 1998. There are 12 Type Ibc SNe with no detections of progenitors in either deep ground-based or Hubble Space Telescope archival imaging. The deepest absolute BVR magnitude limits are between -4 and -5mag. We compare these limits with the observed Wolf-Rayet population in the Large Magellanic Cloud and estimate a 16 percent probability that we have failed to detect such a progenitor by chance. Alternatively, the progenitors evolve significantly before core-collapse or we have underestimated the extinction towards the progenitors. Reviewing the relative rates and ejecta mass estimates from light-curve modelling of Ibc SNe, we find both incompatible with Wolf-Rayet stars with initial masses >25M_{sun}_ being the only progenitors. We present binary evolution models that fit these observational constraints. Stars in binaries with initial masses <~20M_{sun}_ lose their hydrogen envelopes in binary interactions to become low-mass helium stars. They retain a low-mass hydrogen envelope until ~10^4^yr before core-collapse; hence, it is not surprising that Galactic analogues have been difficult to identify.
3305. CORE high-mass star-forming regions
ID:
ivo://CDS.VizieR/J/A+A/648/A66
Title:
CORE high-mass star-forming regions
Short Name:
J/A+A/648/A66
Date:
21 Oct 2021
Publisher:
CDS
Description:
Characterizing the physical and chemical properties of forming massive stars at the spatial resolution of individual high-mass cores lies at the heart of current star formation research. We use sub-arcsecond resolution (~0.4arcsec) observations with the NOrthern Extended Millimeter Array at 1.37mm to study the dust emission and molecular gas of 18 high-mass star-forming regions. With distances in the range of 0.7-5.5kpc this corresponds to spatial scales down to 300-2300au that are resolved by our observations. We combine the derived physical and chemical properties of individual cores in these regions to estimate their ages. The temperature structure of these regions are determined by fitting H_2_CO and CH_3_CN line emission. The density profiles are inferred from the 1.37mm continuum visibilities. The column densities of 11 different species are determined by fitting the emission lines with XCLASS. Within the 18 observed regions, we identify 22 individual cores with associated 1.37mm continuum emission and with a radially decreasing temperature profile. We find an average temperature power-law index of q=0.4+/-0.1 and an average density power-law index of p=2.0+/-0.2 on scales on the order of several 1000au. Comparing these results with values of p derived in the literature suggest that the density profiles remain unchanged from clump to core scales. The column densities relative to N(C18O) between pairs of dense gas tracers show tight correlations. We apply the physical-chemical model MUlti Stage ChemicaL codE (MUSCLE) to the derived column densities of each core and find a mean chemical age of ~60000yrs and an age spread of 20000-100000yrs. With this paper we release all data products of the CORE project available at https://www.mpia.de/core. The CORE sample reveals well constrained density and temperature power-law distributions. Furthermore, we characterize a large variety in molecular richness that can be explained by an age spread confirmed by our physical-chemical modeling. The hot molecular cores show the most emission lines, but we also find evolved cores at an evolutionary stage, in which most molecules are destroyed and thus the spectra appear line-poor again.
3306. Core mass function across Gal. env. II. IRDC clumps
ID:
ivo://CDS.VizieR/J/ApJ/862/105
Title:
Core mass function across Gal. env. II. IRDC clumps
Short Name:
J/ApJ/862/105
Date:
21 Oct 2021
Publisher:
CDS
Description:
We study the core mass function (CMF) within 32 dense clumps in seven infrared dark clouds (IRDCs) with the Atacama Large Millimeter/submillimeter Array via 1.3mm continuum emission at a resolution of ~1". We have identified 107 cores with the dendrogram algorithm, with a median radius of about 0.02pc. Their masses range from 0.261 to 178M_{sun}_. After applying completeness corrections, we fit the combined IRDC CMF with a power law of the form dN/d.logM{propto}M^-{alpha}^ and derive an index of {alpha}~0.86+/-0.11 for M>=0.79M_{sun}_ and {alpha}~0.70+/-0.13 for M>=1.26M_{sun}_, which is a significantly more top-heavy distribution than the Salpeter stellar initial mass function index of 1.35. We also make a direct comparison of these IRDC clump CMF results to those measured in the more evolved protocluster G286 derived with similar methods, which have {alpha}~1.29+/-0.19 and 1.08+/-0.27 in these mass ranges, respectively. These results provide a hint that, especially for the M>=1.26M_{sun}_ range where completeness corrections are modest, the CMF in high pressure, early-stage environments of IRDC clumps may be top-heavy compared to that in the more evolved, global environment of the G286 protoclusters. However, larger samples of cores probing these different environments are needed to better establish the robustness of this potential CMF variation.
3307. Core of the Shapley supercluster at 1.4GHz
ID:
ivo://CDS.VizieR/J/AJ/130/2541
Title:
Core of the Shapley supercluster at 1.4GHz
Short Name:
J/AJ/130/2541
Date:
21 Oct 2021
Publisher:
CDS
Description:
The core of the Shapley supercluster (A3556, A3558, SC 1327-312, SC 1329-313, and A3562) is an ideal region in which to study the effects of cluster mergers on the activity of individual galaxies. This paper presents the most comprehensive radio continuum investigation of the region, relying on a 63 pointing mosaic obtained with the Very Large Array yielding an areal coverage of nearly 7{deg}^2^.
3308. Core rotation period measurements of KIC stars
ID:
ivo://CDS.VizieR/J/ApJ/887/203
Title:
Core rotation period measurements of KIC stars
Short Name:
J/ApJ/887/203
Date:
21 Oct 2021
Publisher:
CDS
Description:
Stars between two and three solar masses rotate rapidly on the main sequence, and the detection of slow core and surface rotation in the core-helium burning phase for these stars places strong constraints on their angular momentum transport and loss. From a detailed asteroseismic study of the mixed-dipole mode pattern in a carefully selected, representative sample of stars, we find that slow core rotation rates in the range reported by prior studies are a general phenomenon and not a selection effect. We show that the core rotation rates of these stars decline strongly with decreasing surface gravity during the core He-burning phase. We argue that this is a model-independent indication of significant rapid angular momentum transport between the cores and envelopes of these stars. We see a significant range in core rotation rates at all surface gravities, with little evidence for a convergence toward a uniform value. We demonstrate using evolutionary models that measured surface rotation periods are a biased tracer of the true surface rotation distribution, and we argue for using stellar models for interpreting the contrast between core and surface rotation rates. The core rotation rates we measure do not have a strong mass or metallicity dependence. We argue that the emerging data strongly favor a model where angular momentum transport is much more efficient during the core He-burning phase than in the shell-burning phases that precede and follow it.
3309. Cores in California molecular cloud
ID:
ivo://CDS.VizieR/J/A+A/620/A163
Title:
Cores in California molecular cloud
Short Name:
J/A+A/620/A163
Date:
21 Oct 2021
Publisher:
CDS
Description:
We extracted 300 cores, of which 33 are protostellar and 267 are starless cores. About 51% (137 of 267) of the starless cores are prestellar cores. Three cores have the potential to evolve into high-mass stars. The prestellar core mass function (CMF) can be well fit by a log-normal form. The high-mass end of the prestellar CMF shows a power-law form with an index {alpha}=-0.9+/-0.1 that is shallower than that of the Galactic field stellar mass function. Combining the mass transformation efficiency ({epsilon}) from the prestellar core to the star of 15+/-1% and the core formation efficiency (CFE) of 5.5%, we suggest an overall star formation efficiency of about 1% in the CMC. In the single-pointing observations with the IRAM 30m telescope, we find that 6 cores show blue-skewed profile, while 4 cores show red-skewed profile. [HCO^+^]/[HNC] and [HCO^+^]/[N_2_H^+^] in protostellar cores are higher than those in prestellar cores; this can be used as chemical clocks. The best-fit chemical age of the cores with line observations is ~50000 years.
3310. Cores in HII regions parameters
ID:
ivo://CDS.VizieR/J/A+A/611/A99
Title:
Cores in HII regions parameters
Short Name:
J/A+A/611/A99
Date:
21 Oct 2021
Publisher:
CDS
Description:
High-mass stars form in much richer environments than those associated with isolated low-mass stars, and once they reach a certain mass, produce ionised (HII) regions. The formation of these pockets of ionised gas are unique to the formation of high-mass stars (M>8M_{sun}_), and present an excellent opportunity to study the final stages of accretion, which could include accretion through the HII region itself. This study of the dynamics of the gas on both sides of these ionisation boundaries in very young HII regions aims to quantify the relationship between the HII regions and their immediate environments. We present high-resolution (~0.5") ALMA observations of nine HII regions selected from the Red MSX Source (RMS, Lumsden et al., Cat. J/ApJS/208/11) survey with compact radio emission and bolometric luminosities greater than 10^4^L_{sun}_. We focus on the initial presentation of the data, including initial results from the radio recombination line H29{alpha} some complementary molecules, and the 256GHz continuum emission.

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