Related papers: A Study of Stochastic Low-Frequency Variability fo…
Modern spectroscopic surveys combined with Gaia distances are enabling reliable estimates of fundamental parameters for hundreds of Galactic O-type stars and the full range of spectral types and luminosity classes. Here we provide updated,…
Classical low surface brightness (LSB) galaxies pose an important challenge to galaxy evolution models. While they are found to host large reservoirs of atomic hydrogen, they display low stellar and star-formation surface densities. Global…
We reanalyzed spectra that were taken as part of the SL2S lens galaxy survey with the goal to obtain the stellar velocity dispersion with a precision and accuracy sufficient for time-delay cosmography. In order to achieve this goal, we…
Using a mass-limited sample of 24um-detected, star-forming galaxies at 0.5<z<1.3, we study the mass-star formation rate (SFR) correlation and its tightness. The correlation is well defined (sigma=0.28dex) for disk galaxies (n_sersic<1.5),…
An evolution of luminosity of galaxies in emission lines or wavelength ranges in which they are sensitive to the star formation process is caused by burning out of the most massive O-class stars during a few million years after a starburst.…
We analyse 829,481 stars from the Next Generation Transit Survey (NGTS) to extract variability periods. We utilise a generalisation of the autocorrelation function (the G-ACF), which applies to irregularly sampled time series data. We…
Stellar evolution models of massive stars are very sensitive to the adopted mass-loss scheme. The magnitude and evolution of mass-loss rates significantly affect the main sequence evolution, and the properties of post-main sequence objects,…
The impact of FUSE upon the fundamental parameters of OB stars and Wolf-Rayet stars is reviewed. The stellar wind signatures available in the far-UV provide us with important additional diagnostics of effective temperature. Together with…
We present a $\approx 11.5$ year adaptive optics (AO) study of stellar variability and search for eclipsing binaries in the central $\sim 0.4$ pc ($\sim 10''$) of the Milky Way nuclear star cluster. We measure the photometry of 563 stars…
Spectroscopic observations have shown for decades that the Wolf-Rayet (WR) phenomenon is ubiquitous among stars with different initial masses. Although much effort to understand the winds from massive WR stars has been presented in the…
We present a spectroscopic study of low-mass galaxies (LMGs;$10^8\leq\rm M_*/M_\odot\leq10^9$) at $z\sim0.15$ in COSMOS field, and compare it to a control sample of intermediate-mass galaxies (IMGs;$10^9\leq\rm M_*/M_\odot\leq10^{10}$) at…
Context. The first magnetic fields in O- and B-type stars that do not belong to the Bp-star class, have been discovered. The cyclic UV wind-line variability, which has been observed in a significant fraction of early-type stars, is likely…
Most galaxies follow well-defined scaling relations of metallicity (O/H), star formation rate (SFR), and stellar mass. However, low-metallicity starbursts, rare in the Local Universe but more common at high redshift, deviate significantly…
The integrated light of a stellar population, measured through photometric filters that are sensitive to the presence of young stars, is often used to infer the star formation rate (SFR) for that population. However, these techniques rely…
I discuss observational evidence -- independent of the direct spectral diagnostics of stellar winds themselves -- suggesting that mass-loss rates for O stars need to be revised downward by roughly a factor of three or more, in line with…
We analyze 4,859 O-stars in the OGLE-III photometric survey of the LMC, including 415 eclipsing binaries (EBs). After accounting for the geometrical probability of eclipses, the period distribution of O-type binaries across $P$ = 2.5-200…
Stellar feedback in dwarf galaxies plays a critical role in regulating star formation via galaxy-scale winds. Recent hydrodynamical zoom simulations of dwarf galaxies predict that the periodic outward flow of gas can change the…
In a companion paper, we have conducted an in-depth analysis of radial velocity jitter of over 600 stars, examining the astrophysical origins including stellar granulation, oscillation, and magnetic activity. In this paper, we highlight a…
Flares are short-lived but energetic manifestations of stellar activity. Studying them is crucial, as they emit intense high-energy radiation that can impact the circumstellar environment, especially the atmospheres of orbiting planets.…
Scaling relations of metallicity (O/H), star formation rate (SFR), and stellar mass give important insight on galaxy evolution. They are obeyed by most galaxies in the Local Universe and also at high redshift. In a companion paper, we…