Related papers: GD-1 Stellar Stream and Cocoon in the DESI Early D…

The Hercules ultra-faint dwarf galaxy (UFD) has long been hypothesized to be tidally disrupting, yet no conclusive evidence has been found for tidal disruption owing partly to difficulties in identifying Hercules member stars. In this work,…

Detailed studies of stellar populations in the halos of the Milky Way and the Andromeda (M 31) galaxies have shown increasing numbers of tidal streams and dwarf galaxies, attesting to a complicated and on-going process of hierarchical…

Stellar streams are essential tracers of the gravitational potential of the Milky Way, with key implications to the problem of dark matter (DM) model distributions, either within or beyond phenomenological $\Lambda$CDM halos. For the first…

Omega Centauri is the most massive globular cluster of the Milky Way, and possesses many peculiar properties. In particular, the cluster contains distinct multiple stellar populations, with a large spread in metallicity and different…

Recently, Carraro (2005) drew attention to the remarkable star cluster Whiting 1 by showing that it lies about 40 kpc from the Sun and is therefore unquestionably a member of the Galactic halo (b=-60.6 deg.). Its CMD indicated that Whiting…

Stellar streams are a promising way to probe the gravitational effects of low-mass dark matter (DM) subhalos. In recent years, there has been a remarkable explosion in the number of stellar streams detected in the Milky Way, and hundreds…

The earliest stages of low-mass star-formation are unclear, but it has been proposed that Chamaeleon-MMS1 is a candidate First Hydrostatic Core (FHSC), the transition stage between a prestellar and protostellar core. This work describes the…

Stellar streams are excellent probes of the gravitational potential in which they evolve. In the Milky Way (MW), globular cluster (GC) streams are routinely used to infer properties about time-dependent perturbations of the underlying…

We report on the first analysis of AstroSat observation of the Z-source GX 5- 1 on February 26-27, 2017. The hardness-intensity plot reveals that the source traced out the horizontal and normal branches. The 0.8-20 keV spectra from…

Studies on the circumstellar structures around evolved stars provide vital information on the evolution of the parent star and the properties of the local interstellar medium. In this work, we present the discovery and characterization of…

The Magellanic HI Stream (~2x10^9 Msun [d/55 kpc]^2) encircling the Galaxy at a distance 'd' is arguably the most important tracer of what happens to gas accreting onto a disk galaxy. Recent observations reveal that the Stream's mass is in…

We present a detailed analysis of deep VLT/X-Shooter observations of the planetary nebula Tc 1. We calculate gas temperature, density, extinction, and abundances for several species from the empirical analysis of the total line fluxes. In…

Dense cores in massive, parsec-scale molecular clumps are sites that harbor protocluster formation. We present results from observations towards a hub-filament structure of a massive Infrared Dark Cloud (IRDC) G14.225-0.506 using the…

We present new 230 GHz Submillimeter Array observations of the candidate first hydrostatic core Per-Bolo 58. We report the detection of a 1.3 mm continuum source and a bipolar molecular outflow, both centered on the position of the…

We use high-resolution N-body simulations to follow the formation and evolution of tidal streams associated to dwarf spheroidal galaxies (dSphs). The dSph models are embedded in dark matter (DM) haloes with either a centrally-divergent…

We report the discovery of a $>1^\circ$ ($\sim50$ kpc) long stellar tidal stream emanating from the dwarf galaxy DDO 44, a likely satellite of Local Volume galaxy NGC 2403 located $\sim70$ kpc in projection from its companion. NGC 2403 is a…

We present surface photometry of a giant, low surface brightness stellar arc in the halo of the nearby spiral galaxy M63 (NGC 5055) that is consistent with being a part of a stellar stream resulting from the disruption of a dwarf satellite…

We have performed mm-wave observations with the IRAM 30m telescope of the 12CO J=2-1 and J=1-0, 13CO J=2-1 and J=1-0, and SiO J=5-4 transitions in the symbiotic stars R Aqr, CH Cyg, and HM Sge. The data were analyzed by means of a simple…

More than a decade ago, the Large Area Telescope aboard the Fermi Gamma-ray Space Telescope unveiled the existence of two gigantic gamma-ray lobes known as the Fermi bubbles. While their origin is still unknown, various studies identified…

The discovery of the most metal-poor stream, C-19, provides us with a fossil record of a stellar structure born very soon after the Big Bang. In this work, we search for new C-19 members over the whole sky by combining two complementary…