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- ID:
- ivo://CDS.VizieR/J/MNRAS/413/223
- Title:
- Magellanic clouds Cepheids JHKs photometry
- Short Name:
- J/MNRAS/413/223
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Period-luminosity relations (PLRs) of type II Cepheids (T2Cs) in the Small Magellanic Cloud (SMC) are derived based on OGLE-III, IRSF/SIRIUS and other data, and these are compared with results for the Large Magellanic Cloud (LMC) and Galactic globular clusters. Evidence is found for a change of the PLR slopes from system to system. Treating the longer period T2Cs (W Vir stars) separately gives an SMC-LMC modulus difference of 0.39+/-0.05mag without any metallicity corrections being applied. This agrees well with the difference in moduli based on different distance indicators, in particular the PLRs of classical Cepheids. The shorter period T2Cs (BL Her stars) give a smaller SMC-LMC difference suggesting that their absolute magnitudes might be affected either by metallicity or by age effects. It is shown that the frequency distribution of T2C periods also changes from system to system.
- ID:
- ivo://CDS.VizieR/J/ApJS/155/401
- Title:
- Magellanic clouds globular clusters ISOCAM obs.
- Short Name:
- J/ApJS/155/401
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Seventeen globular clusters in the Large and Small Magellanic Clouds were observed in the mid-infrared wavelength region with the ISOCAM instrument on board the Infrared Space Observatory (ISO). Observations were made using the broadband filters LW1, LW2, and LW10, corresponding to the effective wavelengths of 4.5, 6.7, and 12{mu}m, respectively. We present the photometry of point sources in each cluster, as well as their precise positions and finding charts.
- ID:
- ivo://CDS.VizieR/J/AJ/162/229
- Title:
- 13 Magellanic Clouds metal-poor stars
- Short Name:
- J/AJ/162/229
- Date:
- 15 Mar 2022
- Publisher:
- CDS
- Description:
- The chemical abundances of a galaxy's metal-poor stellar population can be used to investigate the earliest stages of its formation and chemical evolution. The Magellanic Clouds are the most massive of the Milky Way's satellite galaxies and are thought to have evolved in isolation until their recent accretion by the Milky Way. Unlike the Milky Way's less massive satellites, little is known about the Magellanic Clouds' metal-poor stars. We have used the mid-infrared metal-poor star selection of Schlaufman & Casey and archival data to target nine LMC and four SMC giants for high-resolution Magellan/MIKE spectroscopy. These nine LMC giants with -2.4<~[Fe/H]<~-1.5 and four SMC giants with -2.6<~[Fe/H]<~-2.0 are the most metal-poor stars in the Magellanic Clouds yet subject to a comprehensive abundance analysis. While we find that at constant metallicity these stars are similar to Milky Way stars in their {alpha}, light, and iron-peak elemental abundances, both the LMC and SMC are enhanced relative to the Milky Way in the r-process element europium. These abundance offsets are highly significant, equivalent to 3.9{sigma} for the LMC, 2.7{sigma} for the SMC, and 5.0{sigma} for the complete Magellanic Cloud sample. We propose that the r-process enhancement of the Magellanic Clouds' metal-poor stellar population is a result of the Magellanic Clouds' isolated chemical evolution and long history of accretion from the cosmic web combined with r-process nucleosynthesis on a timescale longer than the core-collapse supernova timescale but shorter than or comparable to the thermonuclear (i.e., Type Ia) supernova timescale.
- ID:
- ivo://CDS.VizieR/J/AJ/128/1606
- Title:
- Magellanic Clouds Photometric Survey: the LMC
- Short Name:
- J/AJ/128/1606
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present our catalog of U, B, V, and I stellar photometry of the central 64deg^2^ area of the Large Magellanic Cloud. Internal and external astrometric and photometric tests using existing optical photometry (U, B, and V from Massey's bright star catalog (Cat. <II/236>) and I from the near-infrared sky survey DENIS) are used to confirm our observational uncertainty estimates. We fit stellar atmosphere models to the optical data to check the consistency of the photometry for individual stars across the passbands and to estimate the line-of-sight extinction. Finally, we use the estimated line-of-sight extinctions to produce an extinction map across the Large Magellanic Cloud, confirm the variation of extinction as a function of stellar population, and produce a simple geometric model for the extinction as a function of stellar population.
- ID:
- ivo://CDS.VizieR/J/AJ/123/855
- Title:
- Magellanic Clouds Photometric Survey: the SMC
- Short Name:
- J/AJ/123/855
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present our catalog of U, B, V, and I stellar photometry of the central 18{deg}^2^ area of the Small Magellanic Cloud. We combine our data with the Two Micron All Sky Survey (2MASS) and Deep Near-Infrared Southern Sky Survey (DENIS) catalogs to provide, when available, U through K_s_ data for stars. Internal and external astrometric and photometric tests using existing optical photometry (U, B, and V from Massey's (ApJS, in press) bright star catalog; B, V, and I from the microlensing database of OGLE; and I from the near-infrared sky survey DENIS) are used to determine the observational uncertainties and identify systematic errors. We fit stellar atmosphere models to the optical data to check the consistency of the photometry for individual stars across the passbands and to estimate the line-of-sight extinction. Finally, we use the estimated line-of-sight extinctions to produce an extinction map across the Small Magellanic Cloud, and we investigate the nature of extinction as a function of stellar population.
- ID:
- ivo://CDS.VizieR/J/A+A/456/451
- Title:
- Magellanic Clouds PNe abundances
- Short Name:
- J/A+A/456/451
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the second part of an optical spectroscopic study of planetary nebulae in the LMC and SMC. The first paper, Leisy & Dennefeld (1996, Cat. <J/A+AS/116/95>), discussed the CNO cycle for those objects where C abundances were available. In this paper we concentrate more on other elemental abundances (such as O, Ne, S, Ar) and their implications for the evolution of the progenitor stars. We use a much larger sample of 183 objects, of which 65 are our own observations, where the abundances have been re-derived in a homogeneous way. For 156 of them, the quality of data is considered to be satisfactory for further analysis.
- ID:
- ivo://CDS.VizieR/J/A+AS/116/95
- Title:
- Magellanic Clouds PNe line intensities
- Short Name:
- J/A+AS/116/95
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present optical and ultraviolet spectroscopic observations of planetary nebulae (PNe) in the Large (LMC) and the Small Magellanic Clouds (SMC). For the visible spectra with highest S/N, line intensities have been measured to a few tenths of a percent of H_{beta}_. UV spectra are used for the determination of carbon abundances. This paper discusses the CNO cycle and its implications. We show that the CN or ON cycles are more effective with lower initial metallicities and are always complete for typeI nebulae. The latter cannot easily be distinguished from non-type I PNe on the basis of N or He abundance alone, as continuity exists in all of the standard diagrams. From the study of the C abundances, we deduce that the 3rd dredge-up is occurring in all PNe: its efficiency too is higher with lower initial metallicities, offering an easy explanation for the higher number of carbon stars found in metal-deficient galaxies. It is shown that this dredged-up carbon is sometimes transformed into nitrogen by Hot-Bottom Burning, but in a few objects only and not even in all the typeI PNe, which therefore do not form a homogeneous class.
- ID:
- ivo://CDS.VizieR/J/A+A/628/A51
- Title:
- Magellanic Clouds reddening map
- Short Name:
- J/A+A/628/A51
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The reddening maps of the Large Magellanic Cloud (LMC) and Small Magellanic Cloud (SMC) are constructed using the Cepheid period-luminosity (P-L) relations. We examine reddening distribution across the LMC and SMC through large data sets on classical Cepheids provided by the OGLE Phase IV survey. We also investigate the age and spatio-temporal distributions of Cepheids to understand the recent star formation history in the LMC and SMC. The V and I band photometric data of 2476 fundamental mode (FU) and 1775 first overtone mode (FO) Cepheids in the LMC, and 2753 FU and 1793 FO Cepheids in the SMC were analysed for their P-L relations. We converted the period of FO Cepheids to the corresponding period of FU Cepheids before combining the two modes of Cepheids. Both galaxies were divided into small segments and combined FU and FO P-L diagrams were drawn in two bands for each segment. The reddening analysis was performed on 133 segments covering a total area of about 154.6deg^2^ in the LMC and 136 segments covering a total area of about 31.3deg^2^ in the SMC. By comparison with well-calibrated P-L relations of these two galaxies, we determined reddening E(V-I) in each segment and equivalent reddening E(B-V) assuming the normal extinction law. The period-age relations were used to derive the age of the Cepheids. Reddening maps were constructed using reddening values in different segments across the LMC and SMC. We find clumpy structures in the reddening distributions of the LMC and SMC. From the reddening map of the LMC, highest reddening of E(V-I)=0.466mag is traced in the region centred at RA~85.13deg, DEC~-69.34deg which is in close vicinity of the star forming HII region 30 Doradus. In the SMC, maximum reddening of E(V-I)=0.189mag is detected in the region centred at RA~12.10deg, DEC~-73.07deg. The mean reddening values in the LMC and SMC are estimated as E(V-I)_LMC_=0.113+/-0.060mag, E(B-V)_LMC_=0.091+/-0.050mag, E(V-I)_SMC_=0.049+/-0.070mag, and E(B-V)_SMC_=0.038+/-0.053mag. The LMC reddening map displays heterogeneous distribution having small reddening in the central region and higher reddening towards the eastern side of the LMC bar. The SMC has relatively small reddening in its peripheral regions but larger reddening towards the south-west region. In these galaxies, we see evidence of a common enhanced Cepheid population at around 200 Myr ago which appears to have occurred due to a close encounter between the two clouds.
- ID:
- ivo://CDS.VizieR/J/AJ/116/180
- Title:
- Magellanic clouds ultraviolet observations
- Short Name:
- J/AJ/116/180
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The catalog is derived from wide-field far-ultraviolet (FUV; 1300-1800{AA}) images of the Large and Small Magellanic Clouds (LMC, SMC) obtained by the Ultraviolet Imaging Telescope (UIT) during the Astro-1 (1990 December 1-10) and Astro-2 (1995 March 2-18) missions. The FUV magnitudes are derived from point-spread function photometry for 37,333 stars in the LMC (the UIT FUV magnitudes for 11,306 stars in the SMC were presented by Cornett et al. (1997AJ....113.1011C), with a completeness limit of m_UV_ ~ 15mag and a detection limit of m_UV_ ~ 17.5. The average uncertainty in the photometry is ~ 0.1mag.
