- 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.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+AS/122/463
- Title:
- Carbon stars in Magellanic Clouds
- Short Name:
- J/A+AS/122/463
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The 16 tables list the heliocentric and galactocentric radial velocities of several hundred carbon stars in the halo of the LMC and SMC. Most of them are newly discovered stars.
- 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.
- ID:
- ivo://CDS.VizieR/J/A+A/330/505
- Title:
- Carbon stars IR emission
- Short Name:
- J/A+A/330/505
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Spectroscopic and photometric data relative to a sample of 55 carbon stars showing the 11.3{mu}m feature have been fitted in the wavelength range between 0.4 and 100{mu}m by means of a radiative transfer model using the laboratory extinction spectra of amorphous carbon and silicon carbide (SiC) grains. The transfer code allows to determine in a self-consistent way the grain equilibrium temperature of the various species at different distances from the central star and gives all the relevant circumstellar parameters which can be very important for the evolutionary study of carbon stars. In order to get meaningful information on the nature and physical properties of the dust grains responsible for the 11.3{mu}m feature and the underlying continuum, the fitting procedure of the spectr a has been applied individually to every single source. For this reason it has been possible to take into account any variation in position and shape of the band from source to source. Our analysis show that all the sources, in addition to the amorphous carbon grains accounting for the continuum emission, need always the presence of {alpha}-SiC particles while some of them require also {beta}-SiC. Moreover, the presence of one or both types of SiC particles seems not correlated neither with the total optical thickness nor with any other physical and geometrical parameters of the circumstellar envelope. The best-fit parameters found in this work have been used to calculate the mass-loss rate from the central stars. The clear correlation, that we find between the strength of the SiC feature and the total mass loss-rate, confirms the results already found by other authors for the same kind of sources and derived from the observed CO emission lines.
- ID:
- ivo://CDS.VizieR/J/A+A/334/609
- Title:
- Carbon stars IR photometry
- Short Name:
- J/A+A/334/609
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present JHKL photometry of a sample of 150 IRAS stars in the third and fourth galactic quadrant with |b|<2{deg} selected according to their IRAS colour (0.160<=[12-25]<=1.156). We identify 27 carbon star candidates using the [12-25] vs. K-L two-colour diagram method. Among them, 10 are listed in the Stephenson's catalogue of carbon stars and 17 are new infrared carbon stars (IRCS) candidates. Their distances are found to be larger than 3kpc. These data are combined with previous data to study the space distribution of IRCS. The number density seems to be independent of the galactocentric distance (R) toward the Galactic Center and to decrease exponentially toward the anticenter. At the present stage, it is not possible to disentangle effects such as incompleteness of the sample, different space distribution law and dependence of the luminosity on metallicity. In particular, we suggest that the apparent scarcity of IRCS in the central direction of the Galaxy (R<5kpc) might be due to a selection effect. From the available data, we have found no IRCS within 1kpc of the Galactic Center.
- ID:
- ivo://CDS.VizieR/J/A+A/589/A36
- Title:
- Carbon stars spectra and photometry values
- Short Name:
- J/A+A/589/A36
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We provide a new collection of spectra of 35 carbon stars obtained with the ESO/VLT X-shooter instrument as part of the X-shooter Spectral Library project. The spectra extend from 0.3um to 2.4um with a resolving power above ~8000. The sample contains stars with a broad range of (J-K) color and pulsation properties located in the Milky Way and the Magellanic Clouds. We show that the distribution of spectral properties of carbon stars at a given (J-K) color becomes bimodal (in our sample) when (J-K) is larger than about 1.5. We describe the two families of spectra that emerge, characterized by the presence or absence of the absorption feature at 1.53um, generally associated with HCN and C_2_H_2_. This feature appears essentially only in large-amplitude variables, though not in all observations. Associated spectral signatures that we interpret as the result of veiling by circumstellar matter, indicate that the 1.53um feature might point to episodes of dust production in carbon-rich Miras.
- ID:
- ivo://CDS.VizieR/J/A+A/539/A51
- Title:
- Catalogue enriched with R CrB stars
- Short Name:
- J/A+A/539/A51
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This catalogue contains 1602 entries. It was created to list objects that have similar near- and mid-infrared characteristics than R Coronae Borealis (RCB) stars which are supergiant and hydrogen-deficient stars known to possess a hot circumstellar shell. It is therefore a catalogue enriched with RCB stars and further spectroscopic follow-ups are needed to reveal the nature of each object. The catalogue was produced from a series of selection criteria on the infrared colour of sources published in the Preliminary WISE data release (2011). These sources spread over 57% of the entire sky. They have also all been detected in each J, H and K bands of the 2MASS catalogue.
- ID:
- ivo://CDS.VizieR/J/AJ/129/729
- Title:
- CCD photometry of luminous stars in M33
- Short Name:
- J/AJ/129/729
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The M33 galaxy is a nearby, relatively metal-poor, late-type spiral. Its proximity and almost face-on inclination means that it projects over a large area on the sky, making it an ideal candidate for wide-field CCD mosaic imaging. Photometry was obtained for more than 106 stars covering a 74'x56' field centered on M33. Main-sequence, supergiant branch, red giant branch, and asymptotic giant branch (AGB) populations are identified and classified based on broadband V and I photometry. Narrowband filters are used to measure spectral features allowing, the AGB population to be further divided into C and M star types. The galactic structure of M33 is examined using star counts, color-color, and color-magnitude-selected stellar populations. We use the C to M star ratio to investigate the metallicity gradient in the disk of M33.
- ID:
- ivo://CDS.VizieR/J/MNRAS/440/1095
- Title:
- Chemical analysis of CH stars
- Short Name:
- J/MNRAS/440/1095
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Results from high-resolution spectral analyses of a selected sample of CH stars are presented. Detailed chemical composition studies of these objects, which could reveal abundance patterns that in turn provide information regarding nucleosynthesis and evolutionary status, are scarce in the literature. We conducted detailed chemical composition studies for these objects based on high-resolution (R~42000) spectra. The spectra were taken from the ELODIE archive and cover the wavelength range from 3900 to 6800{AA}. We estimated the stellar atmospheric parameters, the effective temperature T_eff_, the surface gravity logg, and the metallicity [Fe/H] from local thermodynamic equilibrium analyses using model atmospheres. Estimated temperatures of these objects cover a wide range, from 4550 to 6030K. The surface gravity ranges from 1.8 to 3.8, and the metallicity from -0.18 to -1.4. We report updates on elemental abundances for several heavy elements and present estimates of abundance ratios for Sr, Y, Zr, Ba, La, Ce, Pr, Nd, Sm, Eu and Dy with respect to Fe. For the object HD 188650 we present the first abundance analysis results based on a high-resolution spectrum. Enhancements of heavy elements relative to Fe, which are characteristic of CH stars, are evident from our analyses for most of the objects. A parametric model-based study was performed to understand the relative contributions from the s- and r-processes to the abundances of the heavy elements.
- ID:
- ivo://CDS.VizieR/J/MNRAS/446/2348
- Title:
- Chemical analysis of CH stars. II.
- Short Name:
- J/MNRAS/446/2348
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present detailed chemical analyses for a sample of 12 stars selected from the CH star catalogue of Bartkevicius (1996BaltA...5..217B). The sample includes two confirmed binaries, four objects that are known to show radial velocity variations and the rest with no information on the binary status. A primary objective is to examine if all these objects exhibit chemical abundances characteristics of CH stars, based on detailed chemical composition study using high-resolution spectra. We have used high-resolution (R~42000) spectra from the ELODIE archive (Moultaka et al. 2004PASP..116..693M). These spectra cover 3900 to 6800 {AA} in the wavelength range. We have estimated the stellar atmospheric parameters, the effective temperature T_eff_, the surface gravity log g, and metallicity [Fe/H] from local thermodynamic equilibrium analysis using model atmospheres. Estimated temperatures of these objects cover a wide range from 4200 to 6640 K, the surface gravity from 0.6 to 4.3 and metallicity from -0.13 to -1.5. We report updates on elemental abundances for several heavy elements, Sr, Y, Zr, Ba, La, Ce, Pr, Nd, Sm, Eu and Dy. For the object HD 89668, we present the first abundance analyses results. Enhancement of heavy elements relative to Fe, a characteristic property of CH stars is evident from our analyses in the case of four objects, HD 92545, HD 104979, HD 107574 and HD 204613. A parametric-model-based study is performed to understand the relative contributions from the s- and r-process to the abundances of the heavy elements.
