相关论文: Modelling the Canes Venatici I dwarf spheroidal ga…

We present VLT/FLAMES spectroscopic observations (R~6500) in the CaII triplet region for 470 probable kinematic members of the Sculptor (Scl) dwarf spheroidal galaxy. The accurate velocities (+- 2 km/s) and large area coverage of Scl allow…

SN 2017ein is a narrow-lined Type Ic SN that was found to share a location with a point-like source in the face on spiral galaxy NGC 3938 in pre-supernova images, making SN 2017ein the first credible detection of a Type Ic progenitor.…

What is the mass of the progenitor of the Sagittarius (Sgr) dwarf galaxy? Here, we reassemble the stellar debris using SDSS and 2MASS data to find the total luminosity and likely mass. We find that the luminosity is in the range 9.6-13.2…

We present new FLAMES$+$GIRAFFE spectroscopy of 36 member stars in the isolated Local Group dwarf spheroidal galaxy Tucana. We measure a systemic velocity for the system of $v_{\mathrm{Tuc}}=216.7_{-2.8}^{+2.9}$kms$^{-1}$, and a velocity…

We present a new spectroscopic study of the dwarf galaxy Bootes I (Boo I) with data from the Anglo-Australian Telescope and its AAOmega spectrograph together with the Two Degree Field multi-object system. We observed 36 high-probability Boo…

We present a comparison of semi-analytic models of the phase-space structure of tidal debris with observations of stars associated with the Sagittarius dwarf galaxy (Sgr). We find that many features in the data can be explained by these…

We present and analyze the extensive optical broadband photometry of the Type II SN 2023ixf up to one year after explosion. We find that, when compared to two pre-existing model grids, the bolometric light curve is consistent with…

We report the discovery of a nearby dwarf galaxy in the constellation of Hydrus, between the Large and the Small Magellanic Clouds. Hydrus 1 is a mildy elliptical ultra-faint system with luminosity $M_V\sim$ -4.7 and size $\sim$ 50 pc,…

NGC 205, a close satellite of the M31 galaxy, is our nearest example of a dwarf elliptical galaxy. Photometric and kinematic observations suggest that NGC 205 is undergoing tidal distortion from its interaction with M31. Despite earlier…

We present two simple dynamical models for Sagittarius based on N-body simulations of the progressive disruption of a satellite galaxy orbiting for 12.5 Gyr within a realistic Galactic potential. In both models the satellite initially has…

We report the first detection of a credible progenitor system for a Type Ic supernova (SN Ic), SN 2017ein. We present spectra and photometry of the SN, finding it to be similar to carbon-rich, low-luminosity SNe Ic. Using a post-explosion…

We present a chemodynamical study of the Grus I ultra-faint dwarf galaxy (UFD) from medium-resolution ($R\sim11,000$) Magellan/IMACS spectra of its individual member stars. We identify eight confirmed members of Grus I, based on their low…

VV124 (UGC 4879) is an isolated, dwarf irregular/dwarf spheroidal (dIrr/dSph) transition-type galaxy at a distance of 1.36 Mpc. Previous low-resolution spectroscopy yielded inconsistent radial velocities for different components of the…

We present new and accurate radial velocity (RV) measurements of luminous stars of all ages (old horizontal branch, intermediate--age red clump, and young blue plume, as well as red giants of a range of ages; 20.6<V<22) in the Carina dwarf…

Hercules is a dwarf spheroidal satellite of the Milky Way, found at a distance of about 138 kpc, and showing evidence of tidal disruption. It is very elongated and exhibits a velocity gradient of 16 +/- 3 km/s/kpc. Using this data a…

The recently discovered C-19 stellar stream is a collection of kinematically associated metal-poor stars in the halo of the Milky Way lacking an obvious progenitor. The stream spans an arc of ~15 degrees in the sky, and orbit-fitting…

We report limits in the planetary-mass regime for companions around the nearest single white dwarf to the Sun, van Maanen's star (vMa 2), from deep J-band imaging with Gemini North and Spitzer IRAC mid-IR photometry. We find no resolved…

B,V CCD frames have been used to derive surface brightness profiles for NGC 3201 out to ~18 arcmin. A total of 857 radial velocities with median precision ~1 km/s for 399 member giants have been used to trace the velocity dispersion profile…

We present a first deep colour-magnitude diagram of the putative central region (0.5 deg x 0.5 deg) of the Canis Major stellar over-density (l,b)=(240,-8) found by Martin et al. (2004), which has been proposed as the remnant of a dwarf…

It is of broad interest for galaxy formation theory to carry out a full inventory of the numbers and properties of dwarf galaxies in the Local Volume, both satellites and isolated ones. Ultra-deep imaging in wide areas of the sky with small…