- ID:
- ivo://CDS.VizieR/J/AJ/151/88
- Title:
- LMC NIR Synoptic Survey. II. Wesenheit relations
- Short Name:
- J/AJ/151/88
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new near-infrared (NIR) Cepheid period-Wesenheit (P-W) relations in the LMC using time-series observations from the Large Magellanic Cloud NIR Synoptic Survey. We also derive optical+NIR P-W relations using V and I magnitudes from the Optical Gravitational Lensing Experiment. We employ our new JHK_s_ data to determine an independent distance to the LMC of {mu}_LMC_=18.47+/-0.07 (statistical) mag, using an absolute calibration of the Galactic relations based on several distance determination methods and accounting for the intrinsic scatter of each technique. We also derive new NIR period-luminosity and Wesenheit relations for Cepheids in M31 using observations from the Panchromatic Hubble Andromeda Treasury survey. We use the absolute calibrations of the Galactic and LMC W_J,H_ relations to determine the distance modulus of M31, {mu}_M31_=24.46+/-0.20 mag. We apply a simultaneous fit to Cepheids in several Local Group galaxies covering a range of metallicities (7.7<12+log[O/H]<8.6 dex) to determine a global slope of -3.244+/-0.016 mag/dex for the W_J,H_ relation and obtain robust distance estimates. Our distances are in good agreement with recent TRGB based distance estimates and we do not find any evidence for a metallicity dependence in the NIR P-W relations.
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- ID:
- ivo://CDS.VizieR/J/AJ/154/149
- Title:
- LMC NIR synoptic survey. V. NIR photometry of Miras
- Short Name:
- J/AJ/154/149
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We study the near-infrared properties of 690 Mira candidates in the central region of the Large Magellanic Cloud, based on time-series observations at JHK_s_. We use densely sampled I-band observations from the OGLE project to generate template light curves in the near-infrared and derive robust mean magnitudes at those wavelengths. We obtain near-infrared Period-Luminosity relations for oxygen-rich Miras with a scatter as low as 0.12 mag at K_s_. We study the Period-Luminosity-Color relations and the color excesses of carbon-rich Miras, which show evidence for a substantially different reddening law.
- ID:
- ivo://CDS.VizieR/J/A+A/632/A106
- Title:
- LMC-N11 (LHA 120-N11) [CII], HI, CO spectra
- Short Name:
- J/A+A/632/A106
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The ambiguous origin of the [CII] 158um line in the interstellar medium complicates its use for diagnostics concerning the star-formation rate and physical conditions in photodissociation regions. We investigate the origin of [CII] in order to measure the total molecular gas content, the fraction of CO-dark H_2_ gas, and how these parameters are impacted by environmental effects such as stellar feedback. We observed the giant HII region N 11 in the Large Magellanic Cloud with SOFIA/GREAT. The [CII] line is resolved in velocity and compared to HI and CO, using a Bayesian approach to decompose the line profiles. A simple model accounting for collisions in the neutral atomic and molecular gas was used in order to derive the H_2_ column density traced by C^+^. The profile of [CII] most closely resembles that of CO, but the integrated [CII] line width lies between that of CO and that of HI. Using various methods, we find that [CII] mostly originates from the neutral gas. We show that [CII] mostly traces the CO-dark H_2_ gas but there is evidence of a weak contribution from neutral atomic gas preferentially in the faintest components (as opposed to components with low [CII]/CO or low CO column density). Most of the molecular gas is CO-dark. The CO-dark H_2_ gas, whose density is typically a few 100s/cm^3^ and thermal pressure in the range 10^3.5-5^K/cm^3^, is not always in pressure equilibrium with the neutral atomic gas. The fraction of CO-dark H_2_ gas decreases with increasing CO column density, with a slope that seems to depend on the impinging radiation field from nearby massive stars. Finally we extend previous measurements of the photoelectric-effect heating efficiency, which we find is constant across regions probed with Herschel, with [CII] and [OI] being the main coolants in faint and diffuse, and bright and compact regions, respectively, and with polycyclic aromatic hydrocarbon emission tracing the CO-dark H_2_ gas heating where [CII] and [OI] emit. We present an innovative spectral decomposition method that allows statistical trends to be derived for the molecular gas content using CO, [CII], and HI profiles. Our study highlights the importance of velocity-resolved photodissociation region (PDR) diagnostics and higher spatial resolution for HI observations as future steps.
- ID:
- ivo://CDS.VizieR/J/AcA/63/159
- Title:
- LMC OGLE-III Shallow Survey variable stars
- Short Name:
- J/AcA/63/159
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We describe variable stars found in the data collected during the OGLE-III Shallow Survey covering the I-band magnitude range from 9.7mag to 14.5mag. The main result is the extension of period-luminosity relations for Cepheids up to 134 days. We also detected 82 binary systems and 110 long-period variables not present in the main OGLE catalogs. Additionally 558 objects were selected as candidates for miscellaneous variables.
- ID:
- ivo://CDS.VizieR/J/AcA/62/247
- Title:
- LMC photometric maps from OGLE-III shallow survey
- Short Name:
- J/AcA/62/247
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present photometric maps based on data from the shallow survey in the Large Magellanic Cloud performed as the supplementary project during the third phase of the Optical Gravitational Lensing Experiment (OGLE) . They cover about 40 square degrees in the LMC and contain mean calibrated VI photometry and astrometry of about 1.7million stars. The magnitudes of the objects range from 9.1 to 18.5.
- ID:
- ivo://CDS.VizieR/J/A+AS/121/407
- Title:
- LMC planetary nebulae positions
- Short Name:
- J/A+AS/121/407
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present identifications and accurate positions for about 280 planetary nebulae (PNe) in the Large Magellanic Cloud (LMC). These positions are needed for follow-up ground or space observations. Entire Schmidt plates have been scanned with the MAMA micro-densitometer, and PPM stars used for the astrometric reduction. The precision achieved is always better than 0.5", and better than 0.3" for most of the objects not located close to the border of the plates. Photometry in the B band is provided with an accuracy of about 0.2magnitude, except in too crowded zones where the background cannot be determined. Cross-identifications with IRAS sources have also been tabulated and discussed.
- ID:
- ivo://CDS.VizieR/J/A+A/531/A157
- Title:
- LMC planetary nebulae (VMC Survey II)
- Short Name:
- J/A+A/531/A157
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The VISTA Magellanic Cloud (VMC) survey is assembling a deep, multi-epoch atlas of YJKs photometry across the Magellanic Clouds. Prior to the VMC survey only the brightest Magellanic Cloud PNe (MCPNe) were accessible at near-infrared (NIR) wavelengths. It is now possible for the first time to assemble the NIR properties of MCPNe and to identify contaminating non-PNe mimics which are best revealed at NIR wavelengths (e.g. HII regions and symbiotic stars). To maintain the unique scientific niche that MCPNe occupy these contaminants must be removed. Here we conduct a VMC-led, multi-wavelength study of 102 objects previously classified as PNe that are located within the first six VMC tiles observed. We present images, photometry, lightcurves, diagnostic colour - colour diagrams and spectral energy distributions used to analyse the entire sample. At least five PNe have newly resolved nebula morphologies, a task previously only possible with the HST.
- ID:
- ivo://CDS.VizieR/J/MNRAS/438/2642
- Title:
- LMC PNe multiwavelength photometry
- Short Name:
- J/MNRAS/438/2642
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper examines, compares and plots optical, near- and mid-infrared (MIR) photometric data for 605 planetary nebulae (PNe) in the Large Magellanic Cloud (LMC). With the aid of multiwavelength surveys such as the Spitzer legacy programme Surveying the Agents of a Galaxy's Evolution, the Two Micron All Sky Survey and the Magellanic Cloud Photometric Survey, plots have been constructed to expose the relative contributions from molecular hydrogen, polycyclic aromatic hydrocarbons, forbidden emission lines, warm dust continuum and stellar emission at various bands. Besides identifying trends, these plots have helped to reveal PN mimics including six previously known PNe in the outer LMC which are re-classified as other object types. Together with continuing follow-up optical observations, the data have enabled a substantial reduction in the number of PNe previously tagged as 'likely' and 'possible'. The total number of LMC PNe is adjusted to 715 but with a greater degree of confidence in regard to classification. In each colour-colour plot, the more highly evolved LMC PNe are highlighted for comparison with younger, brighter PNe. The faintest and most evolved PNe typically cluster in areas of colour-colour space occupied by ordinary stars. Possible reasons for the wide disparity in infrared colour-colour ratios, such as evolution and dust composition, are presented for evaluation. A correlation is found between the optical luminosity of PNe, emission-line ratios and the MIR dust luminosity at various bands. Luminosity functions using the four Infrared Array Camera and Multiband Imaging Photometer of Spitzer (MIPS) [24] bands are directly compared, revealing an increasing accumulation of PNe within the brightest two magnitudes at longer wavelengths. A correlation is also found between the MIPS [24] band and the [OIII] 5007 and H{beta} fluxes.
- ID:
- ivo://CDS.VizieR/J/MNRAS/405/1349
- Title:
- LMC PNe [OIII] 5007{AA} and H{beta} flux
- Short Name:
- J/MNRAS/405/1349
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Our previous identification and spectroscopic confirmation of 431 faint, new planetary nebulae (PNe) in the central 25deg^2^ region of the Large Magellanic Cloud (LMC) permit us to now examine the shape of the LMC planetary nebula luminosity function (PNLF) through an unprecedented 10mag range. The majority of our newly discovered and previously known PNe were observed using the 2dF, multi-object fibre spectroscopy system on the 3.9-m Anglo-Australian Telescope and the FLAMES multi-object spectrograph on the 8-m Very Large Telescope. We present reliable [OIII] 5007{AA} and H{beta} flux estimates based on calibrations to well-established PN fluxes from previous surveys and spectroscopic standard stars.
- ID:
- ivo://CDS.VizieR/J/MNRAS/411/1597
- Title:
- LMC point source classification in SAGE-Spec
- Short Name:
- J/MNRAS/411/1597
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the classification of 197 point sources observed with the Infrared Spectrograph in the SAGE-Spec Legacy programme on the Spitzer Space Telescope. We introduce a decision-tree method of object classification based on infrared spectral features, continuum and spectral energy distribution shape, bolometric luminosity, cluster membership and variability information, which is used to classify the SAGE-Spec sample of point sources. The decision tree has a broad application to mid-infrared spectroscopic surveys, where supporting photometry and variability information are available. We use these classifications to make deductions about the stellar populations of the Large Magellanic Cloud and the success of photometric classification methods. We find 90 asymptotic giant branch (AGB) stars, 29 young stellar objects, 23 post-AGB objects, 19 red supergiants, eight stellar photospheres, seven background galaxies, seven planetary nebulae, two HII regions and 12 other objects, seven of which remain unclassified.
