Related papers: Molecules and Chemistry in Red Supergiants
Red Supergiants (RSGs) are among the brightest stars in the local universe, making them ideal candidates with which to probe the properties of their host galaxies. However, current quantitative spectroscopic techniques require spectral…
Early-time observations of the Type II supernovae (SNe) 2013cu and 2013fs have revealed an interaction of ejecta with material near the star surface. Unlike the Type IIn SN2010jl, which interacts with a dense wind for ~1yr, the interaction…
Luminous red galaxies (LRGs) are the most massive galaxies at $z\sim 0.5$ and, by selection, have negligible star formation. These objects have halo masses between those of $L_{*}$ galaxies, whose circumgalactic media (CGM) are observed to…
Red supergiants (RSGs) are a He-burning phase in the evolution of moderately massive stars (10-25 solar masses). For many years, the assumed physical properties of these stars placed them at odds with the predictions of evolutionary theory.…
With the ever faster cadence of untargeted surveys of the sky, the supernova (SN) community will capture in the coming years a growing number of shock breakouts in red-supergiant (RSG) stars. Expecting a high frequency of breakouts within…
Mass loss is an important activity for red supergiants (RSGs) which can influence their evolution and final fate. Previous estimations of mass loss rates (MLRs) of RSGs exhibit significant dispersion due to the difference in method and the…
Red supergiant stars (RSGs) and yellow hypergiant stars (YHGs) are believed to be the high-mass counterparts of stars in the AGB and early post-AGB phases. We study the mass-loss in the post main-sequence evolution of massive stars, through…
The physical origin of red giants (RGs) and red supergiants (RSGs) remains a fundamental question in stellar astrophysics. In Paper II of this series, we investigate the physical mechanisms governing envelope expansion toward the RG/RSG…
Over the last decade, observations of the cool interstellar medium in distant galaxies via molecular and atomic fine structure line emission has gone from a curious look into a few extreme, rare objects, to a mainstream tool to study galaxy…
In this paper we study the oxygen chemistry in the C-rich circumstellar shells of IRC+10216. The recent discoveries of oxygen bearing species (water, hydroxyl radical and formaldehyde) toward this source challenge our current understanding…
I present recent high-resolution submillimeter and millimeter observations of molecular gas and dust in some mergers, luminous galaxy nuclei, and possible mergers. Such observations tell us the behavior and properties of interstellar medium…
We present a search for HI in the circumgalactic medium (CGM) of 21 massive ($\langle \log M_\star \rangle \sim 11.4$), luminous red galaxies (LRGs) at $z\sim0.5$. Using UV spectroscopy of QSO sightlines projected within 500 kpc ($\sim…
Red Midcourse Space Experiment (MSX) Sources (RMSs) are regarded as excellent candidates of massive starforming regions. In order to characterize the chemical properties of massive star formation, we made a systematic study of 87 RMSs in…
We explore the three-dimensional properties of convective, luminous ($L\approx10^{4.5}-10^{5}L_\odot$), Hydrogen-rich envelopes of Red Supergiants (RSGs) based on radiation hydrodynamic simulations in spherical geometry using…
Red supergiants (RSGs), which are progenitors of hydrogen-rich Type II supernovae (SNe), have been known to pulsate from both observations and theory. The pulsations can be present at core collapse and affect the resulting SN. However, SN…
We present HI line profiles for various models of circumstellar shells around red giants. In the calculations we take into account the effect of the background at 21 cm, and show that in some circumstances it may have an important effect on…
Our knowledge of the chemical properties of the circumstellar ejecta of the most massive evolved stars is particularly poor. We aim to study the chemical characteristics of the prototypical yellow hypergiant star, IRC +10420. For this…
The circumnuclear disk (CND) of the Galactic Center is exposed to many energetic phenomena coming from the supermassive black hole Sgr A* and stellar activities. These energetic activities can affect the chemical composition in the CND by…
Red supergiants (RSGs), representing a kind of massive young stellar population, have rarely been used to probe the structure of the Milky Way, mainly due to the long-standing scarcity of Galactic RSG samples. The Gaia BP/RP spectra…
We report high-sensitivity millimetre observations of several molecular species (13CO, HCN, HNC, CN, HCO+ and N2H+) in a sample of compact planetary nebulae. Some species such as HCO+ and CN are particularly abundant compared to envelopes…