- ID:
- ivo://CDS.VizieR/J/AJ/149/117
- Title:
- LMC infrared survey. I. Photometry of Cepheids
- Short Name:
- J/AJ/149/117
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present observational details and first results of a near-infrared (JHK_s_) synoptic survey of the central region of the Large Magellanic Cloud (LMC) using the CPAPIR camera at the CTIO 1.5m telescope. We covered 18 square degrees to a depth of K_s_~16.5mag and obtained an average of 16 epochs in each band at any given location. Our catalog contains more than 3.5x10^6^ sources, including 1417 Cepheid variables previously studied at optical wavelengths by the OGLE survey. Our sample of fundamental-mode pulsators represents a nine-fold increase in the number of these variables with time-resolved, multi-band near-infrared photometry. We combine our large Cepheid sample and a recent precise determination of the distance to the LMC to derive a robust absolute calibration of the near-infrared Leavitt Law for fundamental-mode and first-overtone Cepheids with 10x better constraints on the slopes relative to previous work. We also obtain calibrations for the tip of the red giant branch and the red clump based on our ensemble photometry which are in good agreement with previous determinations.
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- ID:
- ivo://CDS.VizieR/J/AJ/136/1242
- Title:
- LMC long-period variables from MACHO
- Short Name:
- J/AJ/136/1242
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a new analysis of the long-period variables in the Large Magellanic Cloud (LMC) from the MACHO Variable Star Catalog. Three-quarters of our sample of evolved, variable stars have periodic light curves. We characterize the stars in our sample using the multiple periods found in their frequency spectra. Additionally, we use single-epoch Two Micron All Sky Survey measurements to construct the average infrared light curves for different groups of these stars.
- ID:
- ivo://CDS.VizieR/J/A+A/655/A12
- Title:
- LMC N113 and N159W ALMA para-H_2_CO datacubes
- Short Name:
- J/A+A/655/A12
- Date:
- 07 Mar 2022 07:15:12
- Publisher:
- CDS
- Description:
- We mapped the kinetic temperature structure of two massive star-forming regions, N113 and N159W, in the Large Magellanic Cloud (LMC). We have used ~1.6" (~0.4pc) resolution measurements of the para-H_2_CO J_KaKc_=3_03_-2_02_, 3_22_-2_21_, and 3_21_-2_20_ transitions near 218.5GHz to constrain RADEX non local thermodynamic equilibrium models of the physical conditions. The gas kinetic temperatures derived from the para-H_2_CO line ratios 3_22_-2_21_/3_03_-2_02_ and 3_21_-2_20_/3_03_-2_02_ range from 28 to 105K in N113 and 29 to 68K in N159W. Distributions of the dense gas traced by para-H_2_CO agree with those of the 1.3mm dust and Spitzer 8.0um emission, but they do not significantly correlate with the H emission. The high kinetic temperatures (T_kin_>~50K) of the dense gas traced by para-H_2_CO appear to be correlated with the embedded infrared sources inside the clouds and/or young stellar objects in the N113 and N159W regions. The lower temperatures (T_kin_<50K) were measured at the outskirts of the H_2_CO-bearing distributions of both N113 and N159W. It seems that the kinetic temperatures of the dense gas traced by para-H_2_CO are weakly affected by the external sources of the H{alpha} emission. The non thermal velocity dispersions of para-H_2_CO are well correlated with the gas kinetic temperatures in the N113 region, implying that the higher kinetic temperature traced by para-H_2_CO is related to turbulence on a ~0.4pc scale. The dense gas heating appears to be dominated by internal star formation activity, radiation, and/or turbulence. It seems that the mechanism heating the dense gas of the star-forming regions in the LMC is consistent with that in Galactic massive star-forming regions located in the Galactic plane.
- ID:
- ivo://CDS.VizieR/J/AJ/153/154
- Title:
- LMC NIR survey. IV. Type II Cepheid variables
- Short Name:
- J/AJ/153/154
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present time-series observations of Population II Cepheids in the Large Magellanic Cloud at near-infrared (JHK_s_) wavelengths. Our sample consists of 81 variables with accurate periods and optical (VI) magnitudes from the OGLE survey, covering various subtypes of pulsators (BL Herculis, W Virginis, and RV Tauri). We generate light-curve templates using high-quality I-band data in the LMC from OGLE and K_s_-band data in the Galactic bulge from VISTA Variables in Via Lactea survey (2010NewA...15..433M) and use them to obtain robust mean magnitudes. We derive period-luminosity (P-L) relations in the near-infrared and Period-Wesenheit (P-W) relations by combining optical and near-infrared data. Our P-L and P-W relations are consistent with published work when excluding long-period RV Tauris. We find that Pop II Cepheids and RR Lyraes follow the same P-L relations in the LMC. Therefore, we use trigonometric parallax from the Gaia DR1 (Cat. I/337) for VY Pyx and the Hubble Space Telescope parallaxes for k Pav and 5 RR Lyrae variables to obtain an absolute calibration of the Galactic K_s_-band P-L relation, resulting in a distance modulus to the LMC of {mu}_LMC_=18.54+/-0.08 mag. We update the mean magnitudes of Pop II Cepheids in Galactic globular clusters using our light-curve templates and obtain distance estimates to those systems, anchored to a precise late-type eclipsing binary distance to the LMC. We find that the distances to these globular clusters based on Pop II Cepheids are consistent (within 2{sigma}) with estimates based on the M_V_-[Fe/H] relation for horizontal branch stars.
- 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.
- 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.
