Related papers: The Maybe Stream: A Possible Cold Stellar Stream i…
In simple models of the Milky Way, tidally disrupting satellites produce long and thin---nearly one-dimensional---stellar streams. Using astrometric data from the Gaia second data release and photometry from the Dark Energy Survey, we…
Stellar microlensing is a powerful method to constrain compact dark matter models, uncover binary stars, and exoplanets during caustic crossing events. At cosmological distances, {\it James-Webb Space Telescope} ({\it JWST}) is routinely…
We summarize recent attempts to detect warm ionized gas at large galactocentric distances. This includes searching for gas at the edges of spirals, in between cluster galaxies, towards extragalactic HI clouds, and towards high velocity…
We have analyzed the phase space distribution of a sample of about 900 non--kinematically selected low metallicity stars in the solar vicinity. The stars primarily represent the thick disk and halo populations of the Milky Way. We aim to…
Stellar halo substructures were identified using statistical photometric parallax of blue main sequence turnoff stars from fourteen Sloan Digital Sky Survey stripes in the north Galactic cap. Four structures are consistent with previous…
We report the discovery of three new star clusters in the halo of the Local Group dwarf irregular galaxy NGC 6822. These clusters were found in the deep images taken with the MegaPrime at the CFHT, covering a total field of 2 deg x 2 deg.…
Stellar streams are regarded as crucial objects to test galaxy formation models, with their morphology tracing the underlying potentials and their occurrence tracking the assembly history of the galaxies. The existence of one of the most…
Stellar streams are sensitive laboratories for understanding the small-scale structure in our Galaxy's gravitational field. Here, we analyze the morphology of the $300S$ stellar stream, which has an eccentric, retrograde orbit and thus…
We report the discovery of two new candidate stellar systems in the constellation of Cetus using the data from the first two years of the Dark Energy Survey (DES). The objects, DES J0111-1341 and DES J0225+0304, are located at a…
Within the hierarchical framework for galaxy formation, merging and tidal interactions are expected to shape large galaxies to this day. While major mergers are quite rare at present, minor mergers and satellite disruptions - which result…
When a neutron star is compressed to huge densities, it may be converted to a strange star. In property of the event/year rate of a neutron star - strange star binary system, we show that the operational phase of advanced gravitational wave…
Tidal streams from existing and destroyed satellite galaxies populate the outer regions of the Andromeda galaxy (M31). This inhomogeneous debris can be studied without many of the obstacles that plague Milky Way research. We review the…
Using photometry and proper motions from Gaia Early Data Release 3, we detect a 45 degree-long trailing stellar debris stream associated with the old, metal-poor globular cluster NGC 7089. With a width on the order of 100 pc, the extended…
Extending for over 200 degrees across the sky, the Magellanic Stream together with its Leading Arm is the most spectacular example of a gaseous stream in the local Universe. The Stream is an interwoven tail of filaments trailing the…
We argue that the presence of water vapor in the circumstellar outflow of a carbon-rich AGB star is potentially a distinctive signature of extra-solar cometary systems. Detailed models show that at suitable distances from the star, water…
We report Hubble Space Telescope near-infrared NICMOS observations of a remarkable low-luminosity Class I (protostellar) source in the Taurus Molecular Cloud. IRAS 04325+2402 exhibits a complex bipolar scattered light nebula. The central…
Thin stellar streams, such as those resulting from the tidal disruption of globular clusters, have long been known and used as probes of the gravitational potential of our Galaxy, both its visible and dark contents. In particular, the…
The possible association of Galactic globular clusters with the Sgr Stream is shortly reviewed at the light of the most recent observations of the Stream. >= 20 % of the Galactic globular clusters with R_{GC}>= 10 Kpc are found to lie…
The IceCube Neutrino Observatory has recently reported strong evidence for neutrino emission from the Galactic plane. The signal is consistent with model predictions of diffuse emission from cosmic ray propagation in the interstellar…
We report the first detection of CO(1-0) emission from a submillimeter-selected galaxy, using the Green Bank Telescope. We identify the line in the spectrum of SMM J13120+4242 as a broad emission feature at z=3.408, with Delta(V_FWHM)=1040…