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A Preliminary Calibration of the JAGB Method Using Gaia EDR3
Madore, Barry F.; Freedman, Wendy L.; Lee, Abigail J. +2 more
The recently developed J-region asymptotic giant branch (JAGB) method has extraordinary potential as an extragalactic standard candle, capable of calibrating the absolute magnitudes of locally accessible Type Ia supernovae, thereby leading to an independent determination of the Hubble constant. Using Gaia Early Data Release 3 (EDR3) parallaxes, we…
Widespread occurrence of high-velocity upflows in solar active regions
Baker, D.; Brooks, D. H.; Yardley, S. L.
Aims: We performed a systematic study of 12 active regions (ARs) with a broad range of areas, magnetic fluxes, and associated solar activity in order to determine whether there are upflows present at the AR boundaries and, if these upflows exist, whether there is a high-speed asymmetric blue wing component present in them.
Methods: To id…
Gas Infalling Motions in the Envelopes of Very Low Luminosity Objects
Kim, Gwanjeong; Kim, Mi-Ryang; Lee, Chang Won +2 more
We present the results of a single-dish survey toward 95 very low luminosity objects (VeLLOs) in optically thick (HCN 1-0) and thin (N2H+ 1-0) lines performed for the purpose of understanding the physical processes of inward motions in the envelopes of the VeLLOs and characterizing their true nature. The normalized velocity d…
Towards a more rigorous treatment of uncertainties on the velocity distribution of dark matter particles for capture in stars
Lopes, Ilídio; Lacroix, Thomas; Lopes, José
Dark matter (DM) capture in stars offers a rich phenomenology that makes it possible to probe a wide variety of particle DM scenarios in diverse astrophysical environments. In spite of decades of improvements to refine predictions of capture-related observables and better quantify astrophysical and particle-physics uncertainties, the actual impact…
Environmental effects on AGN activity via extinction-free mid-infrared census
Hashimoto, Tetsuya; Goto, Tomotsugu; Kim, Seong Jin +20 more
How does the environment affect active galactic nucleus (AGN) activity? We investigated this question in an extinction-free way by selecting 1120 infrared (IR) galaxies in the AKARI North Ecliptic Pole Wide field at redshift z ≤ 1.2. A unique feature of the AKARI satellite is its continuous nine-band IR filter coverage, providing us with an unprec…
Molecular gas budget and characterization of intermediate-mass star-forming galaxies at z ≈ 2-3
Dahle, H.; Rigby, J. R.; Sharon, K. +9 more
Star-forming galaxies (SFGs) with stellar masses below 1010 M⊙ make up the bulk of the galaxy population at z > 2. The properties of the cold gas in these galaxies can only be probed in very deep observations or by targeting strongly lensed galaxies. Here we report the results of a pilot survey using the Atacama Compact Ar…
The temperatures of red supergiants in low-metallicity environments
Kudritzki, Rolf-Peter; Davies, Ben; González-Torà, Gemma +1 more
The temperatures of red supergiants (RSGs) are expected to depend on metallicity (Z) in such a way that lower Z RSGs are warmer. In this work, we investigate the Z-dependence of the Hayashi limit by analysing RSGs in the low-Z galaxy Wolf-Lundmark-Mellote, and compare with the RSGs in the higher Z environments of the Small Magellanic Cloud and Lar…
Chandra grating spectroscopy of embedded wind shock X-ray emission from O stars shows low plasma temperatures and significant wind absorption
Leutenegger, Maurice A.; Cohen, David H.; Gagné, Marc +4 more
We present a uniform analysis of six examples of embedded wind shock (EWS) O star X-ray sources observed at high resolution with the Chandra grating spectrometers. By modelling both the hot plasma emission and the continuum absorption of the soft X-rays by the cool, partially ionized bulk of the wind we derive the temperature distribution of the s…
HD 344787: a true Polaris analogue?
Plachy, E.; Clementini, G.; Ripepi, V. +10 more
Context. Classical Cepheids (DCEPs) are the most important primary indicators for the extragalactic distance scale, but they are also important objects in their own right, allowing us to place constraints on the physics of intermediate-mass stars and the pulsation theories.
Aims: We have investigated the peculiar DCEP HD 344787, which is know…
An investigation of open cluster Melotte 72 using Gaia DR2
Hendy, Yasser; Tadross, Ashraf
The estimation of the main parameters of star clusters is significant in astrophysical studies. The most important aspect of using the Gaia DR2 survey lies in the positions, parallax, and proper motions of cluster stars with homogeneous photometry that make the membership probability determine with high accuracy. In this respect, depending on Gaia…