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701. Capodimonte Deep Field
ID:
ivo://CDS.VizieR/J/A+A/428/339
Title:
Capodimonte Deep Field
Short Name:
J/A+A/428/339
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the Capodimonte Deep Field (OACDF), a deep field covering an area of 0.5{deg}^2^ in the B, V, R optical bands plus six medium-band filters in the wavelength range 773-913nm. The field reaches the following limiting magnitudes: B_AB_~25.3, V_AB_~24.8 and R_AB_~25.1 and contains ~50000 extended sources in the magnitude range 18<=R_AB_<=25.0. Hence, it is intermediate between deep pencil beam surveys and very wide but shallow surveys.
702. Carbon star in Magellanic Cloud
ID:
ivo://CDS.VizieR/J/MNRAS/376/313
Title:
Carbon star in Magellanic Cloud
Short Name:
J/MNRAS/376/313
Date:
21 Oct 2021
Publisher:
CDS
Description:
Dust radiative transfer models are presented for 60 carbon stars in the Magellanic Clouds (MCs) for which 535m Spitzer infrared spectrograph (IRS) spectra and quasi-simultaneous ground-based JHKL photometry are available. From the modelling, the luminosity and mass-loss rate are derived (under the assumption of a fixed expansion velocity and dust-to-gas ratio), and the ratio of silicon carbide (SiC) to amorphous carbon (AMC) dust is also derived. This ratio is smaller than observed in Galactic carbon stars, as has been noted before. Light curves for 36 objects can be retrieved from the massive compact halo object (MACHO) and optical gravitational lensing experiment (OGLE) data bases, and periods can be derived for all but two of these. Including data from the literature, periods are available for 53 stars.
703. Carbon stars and DQ white dwarfs from SDSS-DR7+DR8
ID:
ivo://CDS.VizieR/J/ApJ/765/12
Title:
Carbon stars and DQ white dwarfs from SDSS-DR7+DR8
Short Name:
J/ApJ/765/12
Date:
21 Oct 2021
Publisher:
CDS
Description:
Among stars showing carbon molecular bands (C stars), the main-sequence dwarfs, likely in post-mass transfer binaries, are numerically dominant in the Galaxy. Via spectroscopic selection from the Sloan Digital Sky Survey, we retrieve 1220 high galactic latitude C stars, ~5 times more than previously known, including a wider variety than past techniques such as color or grism selection have netted, and additionally yielding 167 DQ white dwarfs. Of the C stars with proper motion measurements, we identify 69% clearly as dwarfs (dCs), while ~7% are giants. The dCs likely span absolute magnitudes M_i_ from ~6.5 to 10.5. "G-type" dC stars with weak CN and relatively blue colors are probably the most massive dCs still cool enough to show C_2_bands. We report Balmer emission in 22 dCs, none of which are G-types. We find 8 new DA/dC stars in composite spectrum binaries, quadrupling the total sample of these "smoking guns" for AGB binary mass transfer. Eleven very red C stars with strong red CN bands appear to be "N"-type AGB stars at large Galactocentric distances, one likely a new discovery in the dIrr galaxy Leo A. Two such stars within 30' of each other may trace a previously unidentified dwarf galaxy or tidal stream at ~40 kpc. We explore the multiwavelength properties of the sample and report the first X-ray detection of a dC star, which shows strong Balmer emission. Our own spectroscopic survey additionally provides the dC surface density from a complete sample of dwarfs limited by magnitude, color, and proper motion.
704. Carbon stars from LAMOST DR2 data
ID:
ivo://CDS.VizieR/J/ApJS/226/1
Title:
Carbon stars from LAMOST DR2 data
Short Name:
J/ApJS/226/1
Date:
21 Oct 2021
Publisher:
CDS
Description:
In this work, we present the new catalog of carbon stars from the LAMOST DR2 catalog. In total, 894 carbon stars are identified from multiple line indices measured from the stellar spectra. We are able to identify the carbon stars by combining the CN bands in the red end with C_2_ and other lines. Moreover, we also classify the carbon stars into spectral sub-types of C-H, C-R, and C-N. These sub-types show distinct features in the multi-dimensional line indices, implying that in the future they can be used to identify carbon stars from larger spectroscopic data sets. While the C-N stars are clearly separated from the others in the line index space, we find no clear separation between the C-R and C-H sub-types. The C-R and C-H stars seem to smoothly transition from one to another. This may hint that the C-R and C-H stars may not be different in their origins, instead their spectra look different because of different metallicities. Due to the relatively low spectral resolution and lower signal-to-noise ratio, the ratio of ^12^C/^13^C is not measured and thus the C-J stars are not identified.
705. Carbon stars from LAMOST using machine learning
ID:
ivo://CDS.VizieR/J/ApJS/234/31
Title:
Carbon stars from LAMOST using machine learning
Short Name:
J/ApJS/234/31
Date:
21 Oct 2021
Publisher:
CDS
Description:
In this work, we present a catalog of 2651 carbon stars from the fourth Data Release (DR4) of the Large Sky Area Multi-Object Fiber Spectroscopy Telescope (LAMOST). Using an efficient machine-learning algorithm, we find these stars from more than 7 million spectra. As a by-product, 17 carbon-enhanced metal- poor turnoff star candidates are also reported in this paper, and they are preliminarily identified by their atmospheric parameters. Except for 176 stars that could not be given spectral types, we classify the other 2475 carbon stars into five subtypes: 864 C-H, 226 C-R, 400 C-J, 266 C-N, and 719 barium stars based on a series of spectral features. Furthermore, we divide the C-J stars into three subtypes, C-J(H), C-J(R), and C-J(N), and about 90% of them are cool N-type stars as expected from previous literature. Besides spectroscopic classification, we also match these carbon stars to multiple broadband photometries. Using ultraviolet photometry data, we find that 25 carbon stars have FUV detections and that they are likely to be in binary systems with compact white dwarf companions.
706. Carbon stars from the Hamburg/ESO survey
ID:
ivo://CDS.VizieR/J/A+A/375/366
Title:
Carbon stars from the Hamburg/ESO survey
Short Name:
J/A+A/375/366
Date:
21 Oct 2021
Publisher:
CDS
Description:
This catalog contains 403 Faint High Latitude Carbon (FHLC) stars selected from the digitized objective prism plates of the Hamburg/ESO Survey (HES). Because of the ~15{AA} spectral resolution and high signal-to-noise ratio of the HES prism spectra, our automated procedure based on the detection of C_2_ and CN molecular bands permits high-confidence identification of carbon stars without the need for follow-up spectroscopy. 329 plates (87% of the survey) were examined, covering 6400deg^2^ to a magnitude limit of V~16.5. The catalog lists coordinates, photometry, and carbon band indices for 403 FHLC stars found in the Hamburg/ESO survey. B_J_ magnitudes are accurate to better than +/-0.2mag, including zero point errors. V magnitudes, B-V and U-B colors were derived by the procedure described in Christlieb et al. (2001A&A...366..898C). We also list an object classification for the sources, where "stars", "bright" and "ext" refer to point sources, sources above a saturation threshold, and sources detected as extended in DSS I images, respectively. We do not list V, B-V and U-B for saturated objects, because our color calibrations are not valid for them. Finally, we list two selection flags.
707. Carbon stars in IC10
ID:
ivo://CDS.VizieR/J/A+A/424/125
Title:
Carbon stars in IC10
Short Name:
J/A+A/424/125
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present wide field CFH12K observations of the highly reddened Local Group galaxy IC 10. Using R,I,CN and TiO filters we identify 676 carbon stars in the field of IC 10. After mapping the reddening in the field, from the colours of the G dwarfs seen along the line of sight, we determine the mean apparent magnitude of the C star population to be <I_0_>=19.78, leading to a true modulus of (m-M)_0_=24.35+/-0.11 (741+/-37kpc). The old red giant stars define an asymmetric halo. With a halo diameter of at least 30', IC 10 is among the largest dwarfs of the Local Group. The surface density of C stars follows a radial power law with a scale length of 2.36', a value nearly identical to the scale length defined by the old giants thus IC 10 has a stellar halo where the old and intermediate-age populations are well mixed.
708. Carbon stars in the Galaxy and its satellites
ID:
ivo://CDS.VizieR/J/MNRAS/453/2653
Title:
Carbon stars in the Galaxy and its satellites
Short Name:
J/MNRAS/453/2653
Date:
21 Oct 2021
Publisher:
CDS
Description:
We assemble 121 spectroscopically confirmed halo carbon stars, drawn from the literature, exhibiting measurable variability in the Catalina Surveys. We present their periods and amplitudes, which are used to estimate distances from period-luminosity relationships. The location of the carbon stars - and their velocities when available - allow us to trace the streams of the Sagittarius (Sgr) dwarf spheroidal galaxy. These are compared to a canonical numerical simulation of the accretion of Sgr. We find that the data match this model well for heliocentric distances of 15-50kpc, except for a virtual lack of carbon stars in the trailing arm just north of the Galactic plane, and there is only tentative evidence of the leading arm south of the plane. The majority of the sample can be attributed to the Sgr accretion. We also find groups of carbon stars which are not part of Sgr; most of which are associated with known halo substructures. A few have no obvious attribution and may indicate new substructure. We find evidence that there may be a structure behind the Sgr leading stream apocentre, at ~100kpc, and a more distant extension to the Pisces Overdensity also at ~100kpc. We study a further 75 carbon stars for which no good period data could be obtained, and for which NIR magnitudes and colours are used to estimate distances. These data add support for the features found at distances beyond 100kpc.
709. Carina nebula optically identified YSOs
ID:
ivo://CDS.VizieR/J/A+A/567/A109
Title:
Carina nebula optically identified YSOs
Short Name:
J/A+A/567/A109
Date:
21 Oct 2021
Publisher:
CDS
Description:
The low obscuration and proximity of the Carina nebula make it an ideal place to study the ongoing star formation process and impact of massive stars on low-mass stars in their surroundings. To investigate this process, we have generated a new catalogue of the pre-main-sequence (PMS) stars in the Carina west (CrW) region and studied their nature and spatial distribution. We have also determined various parameters (reddening, reddening law, age, mass) which are further used to estimate the initial mass function (IMF) and K-band luminosity function (KLF) for the region under study. We obtained deep UBVRI H{alpha} photometric data of the field situated to the west of the main Carina nebula and centered around WR22. Medium-resolution optical spectroscopy of a subsample of X-ray selected objects along with archival data sets from Chandra, XMM-Newton and 2MASS surveys are used for the present study. Our spectroscopic results indicate that the majority of the X-ray sources are late spectral type stars. The region shows a large amount of differential reddening with minimum and maximum values of E(B-V) as 0.25 and 1.1mag, respectively. Our analysis reveals that the total to selective absorption ratio R_V_ is ~3.7+/-0.1 suggesting an abnormal grain size in the observed region. We identify 467 young stellar objects (YSOs) and study their characteristics. The ages and masses of the 241 optically identified YSOs range from ~0.1 to 10Myr and ~0.3 to 4.8M_{sun}_, respectively. However, the majority of them are younger than 1Myr and have masses below 2M_{sun}_. The high mass star WR22 does not seem to have contributed to the formation of YSOs in the CrW region. The initial mass function slope, Gamma in this region is found to be -1.13+/-0.20 in the mass range of 0.5<M/M_{sun}_<4.8. The K-band luminosity function slope ({alpha}) is also estimated as 0.31+/-0.01. We also performed minimum spanning tree analysis of the YSOs in this region which reveals that there are at least ten YSO cores associated with the molecular cloud and that leads to an average core radius and median branch length 0.43pc and 0.28pc, respectively.
710. Carina project IX: UBVI data of Carina variables
ID:
ivo://CDS.VizieR/J/ApJ/814/71
Title:
Carina project IX: UBVI data of Carina variables
Short Name:
J/ApJ/814/71
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present new multiband (UBVI) time-series data of helium burning variables in the Carina dwarf spheroidal galaxy. The current sample includes 92 RR Lyrae --six of them are new identifications-- and 20 Anomalous Cepheids, one of which is new identification. The analysis of the Bailey diagram shows that the luminosity amplitude of the first overtone component in double-mode variables is located along the long-period tail of regular first overtone variables, while the fundamental component is located along the short-period tail of regular fundamental variables. This evidence further supports the transitional nature of these objects. Moreover, the distribution of Carina double-mode variables in the Petersen diagram (P_1_/P_0_ versus P_0_) is similar to metal-poor globulars (M15, M68), to the dwarf spheroidal Draco, and to the Galactic Halo. This suggests that the Carina old stellar population is metal-poor and affected by a small spread in metallicity. We use trigonometric parallaxes for five field RR Lyrae stars to provide an independent estimate of the Carina distance using the observed reddening free Period-Wesenheit [PW,(BV)] relation. Theory and observations indicate that this diagnostic is independent of metallicity. We found a true distance modulus of {mu}=20.01+/-0.02 (standard error of the mean)+/-0.05 (standard deviation) mag. We also provided independent estimates of the Carina true distance modulus using four predicted PW relations (BV, BI, VI, BVI) and we found: {mu}=(20.08+/-0.007+/-0.07)mag, {mu}=(20.06+/-0.006+/-0.06)mag, {mu}=(20.07+/-0.008+/-0.08)mag, and {mu}=(20.06+/-0.006+/-0.06)mag. Finally, we identified more than 100 new SX Phoenicis stars that together with those already known in the literature (340) make Carina a fundamental laboratory for constraining the evolutionary and pulsation properties of these transitional variables.