scholarly journals The mid-infrared Leavitt law for classical Cepheids in the Magellanic Clouds

2020 ◽  
Vol 500 (1) ◽  
pp. 817-837
Author(s):  
Abigail H Chown ◽  
Victoria Scowcroft ◽  
Stijn Wuyts
Keyword(s):  
Hubble Space Telescope ◽  
Zero Point ◽  
Large Magellanic Cloud ◽  
Magellanic Clouds ◽  
Light Curves ◽  
Log P ◽  
Mid Infrared ◽  
Space Telescope ◽  
Classical Cepheids ◽  
Combining Data

ABSTRACT The Cepheid Leavitt Law (LL), also known as the Period–Luminosity relation, is a crucial tool for assembling the cosmic distance ladder. By combining data from the OGLE-IV catalogue with mid-infrared photometry from the Spitzer Space Telescope, we have determined the 3.6 and 4.5 $\mu$m LLs for the Magellanic Clouds using ∼5000 fundamental-mode classical Cepheids. Mean magnitudes were determined using a Monte Carlo Markov Chain (MCMC) template fitting procedure, with template light curves constructed from a subsample of these Cepheids with fully phased, well-sampled light curves. The dependence of the Large Magellanic Cloud LL coefficients on various period cuts was tested, in addition to the linearity of the relationship. The zero-point of the LL was calibrated using the parallaxes of Milky Way Cepheids from the Hubble Space Telescope and Gaia Data Release 2. Our final calibrated relations are M[3.6] = −3.246(±0.008)(log (P) − 1.0) − 5.784(±0.030) and M[4.5] = −3.162(±0.008)(log (P) − 1.0) − 5.751(±0.030).

Erratum: "Hubble Space Telescope Observations of Oxygen-Rich Supernova Remnants in the Magellanic Clouds. I. Narrowband Imaging of N132D in the LMC" [A. J. 112,2,509(1996)]

1996 ◽  
Vol 112 ◽  
pp. 2350
Author(s):  
Jon A. Morse ◽  
William P. Blair ◽  
Michael A. Dopita ◽  
John P. Hughes ◽  
Robert P. Kirshner ◽  
...  
Keyword(s):  
Supernova Remnants ◽  
Hubble Space Telescope ◽  
Magellanic Clouds ◽  
Space Telescope ◽  
Narrowband Imaging

scholarly journals CSI in Supernova Remnants

2017 ◽  
Vol 12 (S331) ◽  
pp. 81-85
Author(s):  
You-Hua Chu
Keyword(s):  
Supernova Remnants ◽  
Hubble Space Telescope ◽  
Orbital Plane ◽  
Large Magellanic Cloud ◽  
Close Binary System ◽  
Close Binary ◽  
Binary Interaction ◽  
Space Telescope ◽  
Multi Wavelength ◽  
Mass Ejection

AbstractSupernovae (SNe) explode in environments that have been significantly modified by the SN progenitors. For core-collapse SNe, the massive progenitors ionize the ambient interstellar medium (ISM) via UV radiation and sweep the ambient ISM via fast stellar winds during the main sequence phase, replenish the surroundings with stellar material via slow winds during the luminous blue variable (LBV) or red supergiant (RSG) phase, and sweep up the circumstellar medium (CSM) via fast winds during the Wolf-Rayet (WR) phase. If a massive progenitor was in a close binary system, the binary interaction could have caused mass ejection in certain preferred directions, such as the orbital plane, and even bipolar outflow/jet. As a massive star finally explodes, the SN ejecta interacts first with the CSM that was ejected and shaped by the star itself. As the newly formed supernova remnant (SNR) expands further, it encounters interstellar structures that were shaped by the progenitor from earlier times. Therefore, the structure and evolution of a SNR is largely dependent on the initial mass and close binarity of the SN progenitor. The Large Magellanic Cloud (LMC) has an excellent sample of over 50 confirmed SNRs that are well resolved by Hubble Space Telescope, Chandra X-ray Observatory, and Spitzer Space Telescope. These multi-wavelength observations allow us to conduct stellar forensics in SNRs and understand the wide variety of morphologies and physical properties of SNRs observed.

scholarly journals The distance to the Large Magellanic Cloud from first overtone RR Lyrae variables

2004 ◽  
Vol 193 ◽  
pp. 180-183
Author(s):  
A.V. Muzzin ◽  
C.M. Clement ◽  
D.R. Alves ◽  
Keyword(s):  
Fourier Coefficients ◽  
Large Magellanic Cloud ◽  
Light Curves ◽  
Log P ◽  
Distance Modulus ◽  
P Values ◽  
Rr Lyrae ◽  
Visual Distance ◽  
Bona Fide ◽  
Absolute Magnitudes

AbstractFourier coefficients have been derived for the V and R light curves of 330 bona fide RR Lyrae first-overtone (RR1) pulsators in 16 MACHO fields near the bar of the LMC. We use the Fourier phase parameter ɸ31 and log P values to select a subsample of these stars which are similar to the RR1s in the Galactic globular cluster M5. Assuming that the M5-like stars in the LMC have absolute magnitudes comparable to the HB stars in M5, we use independent studies to derive their mean absolute V magnitude and compute a visual distance modulus of μLMC = 18.43 ± 0.06 (statistical) ±0.16 (systematic). By selecting stars on the basis of their light curve parameters, we are able to derive a distance modulus that does not depend on the somewhat poorly determined Mv – [Fe/H] relation for RR Lyr stars.

scholarly journals VERTICAL ATMOSPHERIC STRUCTURE IN A VARIABLE BROWN DWARF: PRESSURE-DEPENDENT PHASE SHIFTS IN SIMULTANEOUS HUBBLE SPACE TELESCOPE - SPITZER LIGHT CURVES

2012 ◽  
Vol 760 (2) ◽  
pp. L31 ◽  
Author(s):  
Esther Buenzli ◽  
Dániel Apai ◽  
Caroline V. Morley ◽  
Davin Flateau ◽  
Adam P. Showman ◽  
...  
Keyword(s):  
Hubble Space Telescope ◽  
Phase Shifts ◽  
Light Curves ◽  
Brown Dwarf ◽  
Space Telescope ◽  
Atmospheric Structure

scholarly journals Period–luminosity–metallicity relation of classical Cepheids

2020 ◽  
Vol 642 ◽  
pp. A230
Author(s):  
V. Ripepi ◽  
G. Catanzaro ◽  
R. Molinaro ◽  
M. Marconi ◽  
G. Clementini ◽  
...  
Keyword(s):  
Near Infrared ◽  
Data Gathering ◽  
Hubble Constant ◽  
Zero Point ◽  
Total Sample ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Point Of View ◽  
Classical Cepheids ◽  
Metal Abundance

Context. Classical Cepheids (DCEPs) are the most important primary indicators for the extragalactic distance scale. Establishing the dependence on metallicity of their period–luminosity and period–Wesenheit (PL and PW) relations has deep consequences for the estimate of the Hubble constant (H0). Aims. We investigate the dependence on metal abundance ([Fe/H]) of the PL and PW relations for Galactic DCEPs. Methods. We combined proprietary and literature photometric and spectroscopic data, gathering a total sample of 413 Galactic DCEPs (372 fundamental mode, DCEP_F, and 41 first-overtone, DCEP_1O) and constructed new metallicity-dependent PL and PW relations in the near-infrared adopting the astrometry-based luminosity. Results. We find indications that the slopes of the PL(KS) and PW(J, KS) relations for Galactic DCEPs might depend on metallicity on the basis of the comparison with the Large Magellanic Cloud relationships. Therefore we used a generalized form of the PL and PW relations to simultaneously take the metallicity dependence of the slope and intercept of these relations into account. Conclusions. We calculated PL and PW relations that for the first time explicitly include a metallicity dependence of the slope and intercept terms. The quality of the available data is insufficient, however, and we cannot yet present conclusive results, but they are relevant from a methodological point of view. The new relations are linked to the geometric measurement of the distance to the Large Magellanic Cloud and allowed us to estimate a Gaia DR2 parallax zero-point offset Δϖ = 0.0615 ± 0.004 mas from the dataset of DCEPs used in this work.

scholarly journals Massive Star Formation in the Ultraviolet Observed with the Hubble Space Telescope

Galaxies ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 13 ◽  
Author(s):  
Claus Leitherer
Keyword(s):  
Star Formation ◽  
Massive Star ◽  
Hubble Space Telescope ◽  
Spectral Synthesis ◽  
Star Clusters ◽  
Large Magellanic Cloud ◽  
H Ii Regions ◽  
Massive Star Formation ◽  
Space Telescope ◽  
Star Forming

Spectroscopic observations of a massive star formation in the ultraviolet and their interpretation are reviewed. After a brief historical retrospective, two well-studied resolved star clusters and the surrounding H II regions are introduced: NGC 2070 in the Large Magellanic Cloud and NGC 604 in M33. These regions serve as a training set for studies of more distant clusters, which can no longer be resolved into individual stars. Observations of recently formed star clusters and extended regions in star-forming galaxies in the nearby universe beyond the Local Group are presented. Their interpretation relies on spectral synthesis models. The successes and failures of such models are discussed, and future directions are highlighted. I present a case study of the extraordinary star cluster and giant H II region in the blue compact galaxy II Zw 40. The review concludes with a preview of two upcoming Hubble Space Telescope programs: ULLYSES, a survey of massive stars in nearby galaxies, and CLASSY, a study of massive star clusters in star-forming galaxies.

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