Related papers: What next for the Likely Pre-Supernova, HD 179821?
Many aspects of the evolutionary phase in which Asymptotic Giant Branch stars (AGB stars) are in transition to become Planetary Nebulae (PNe) are still poorly understood. An important question is how the circumstellar envelopes of AGB stars…
We present several molecular line emission arcsec and subarcsec observations obtained with the Submillimeter Array (SMA) in the direction of the massive protostar IRAS 18162-2048, the exciting source of HH 80-81. The data clearly indicates…
Cassiopeia A (Cas A) as the nearby young remnant of a core-collapse supernova is the best candidate for astrophysical studies in supernova explosion and its environment. We studied hard X-ray emissions from Cas A using the ten-year data of…
The Young Stellar Object (YSO) W33A is one of the best known examples of a massive star still in the process of forming. Here we present Gemini North ALTAIR/NIFS laser-guide star adaptive-optics assisted K-band integral-field spectroscopy…
We report the detection of CO molecular line emission in the z=4.5 millimeter-detected galaxy COSMOS_J100054+023436 (hereafter: J100+0234) using the IRAM Plateau de Bure interferometer (PdBI) and NRAO's Very Large Array (VLA). The CO(4-3)…
We present 1500 cycles of hydrogen shell flashes on a 1.38 M_sun white dwarf (WD) for a mass accretion rate of 1.6 x 10^{-7} M_sun yr^{-1}, the mass ejection of which is calculated consistently with the optically thick winds. This model…
There are two outstanding issues regarding the neutron-star merger event GW170817: the nature of the compact remnant and the interstellar shock. The mass of the remnant of GW170817, $\sim$2.7 $M_\odot$, implies the remnant could be either a…
Herbig-Haro objects are regions of shocked gas and dust which are produced when collimated outflows from a protostar interact with the surrounding dense gas. They have many similarities to supernova remnants which are interacting with…
Blue straggler, which are stars that appear to be younger than they should be, are an important population of unusual stars in both stellar clusters and the halo field of the Galaxy. Most formation scenarios evoke either stellar collisions…
A recently discovered young, high-velocity giant star J01020100-7122208 is a good candidate of hypervelocity star ejected from the Galactic center, although it has a bound orbit. If we assume that this star was ejected from the Galactic…
The post-main-sequence evolution of massive stars involves phases of intense, often eruptive mass loss, including the B[e] supergiant phase. These hot stars are surrounded by cool, dense circumstellar disks that host complex chemistry,…
A standard fireball/afterglow model of a gamma-ray burst relates the event to a merging neutron star binary, or a neutron star - black hole binary, which places the events far away from star forming regions, and is thought to have an energy…
Magnetized hypermassive neutron stars (HMNSs) have been proposed as a way for neutron star (NS) mergers to produce high electron fraction, high velocity ejecta, as required by kilonova models to explain the observed light curve of GW170817.…
The Galactic supernova remnant HESS J1534-571 (also known as G323.7-1.0) has a shell-like morphology in TeV gamma-ray emission and is a key object in the study of cosmic ray origin. Little is known about its distance and local environment.…
Submillimeter Array 1.3mm line and continuum observations toward the young massive star-forming region IRAS18182-1433 are presented. The data are complemented with short-spacing CO(2-1) observations and SiO(1-0) data from the VLA. Multiple…
There is increasing evidence that low mass stars with circumstellar disks can be born close to massive stars, in some cases within tenths of a pc. If the disks have lifetimes greater than those of the more massive stars, they are exposed to…
We report the discovery with the Parkes radio telescope of a pulsar associated with the ~ 1700 yr-old oxygen-rich composite supernova remnant G292.0+1.8. PSR J1124-5916 has period 135 ms and period derivative 7.4e-13, implying…
An almost perfect round hole of CO-line emission with a diameter of 3.7 pc was found in a molecular cloud (MC) centered on G35.75-0.25 ($l = 35^\circ.75, b = -0^\circ.25$) at radial velocity of 28 km s$^{-1}$. The hole is quiet in radio…
We use a hydro-and-radiative-transfer code to explore the behavior of a very massive star (VMS) after a giant eruption -- i.e., following a supernova impostor event. Beginning with reasonable models for evolved VMSs with masses of…
Gas-rich major mergers in high-redshift proto-clusters are important events, perhaps leading to the creation of the slowly rotating remnants seen in the cores of clusters in the present day. Here, we present a deep Jansky Very Large Array…