We present analysis of nearly 1,000 near-infrared, integrated light spectra from APOGEE in the inner $\sim$7 kpc M31. utilize full spectrum fitting with A-LIST simple stellar population spectral templates that represent a stars same age, [M/H], and [$\alpha$/M]. With this, we determine mean kinematics, metallicities, $\alpha$ abundances, ages populations M31's bar, bulge, disk ($\sim$4-7 kpc). ...

Abstract Using the γ -ray data obtained with Large Area Telescope on board Fermi Gamma-ray Space (Fermi) for ∼14 yr, we examine high-energy emission emanating from center of Andromeda galaxy M31. Different previously reported results, which show a seemingly extended source, instead find two individual point sources, one consistent being at and 0.°4 southeast center. The former is well described...

We used radio observations of the neighbor galaxy M31 in order to put constraints on the dark matter particle mass and annihilation cross section. Dark matter annihilation in M31 halo produces highly energetic leptons, which emit synchrotron radiation on radio frequencies in the galactic magnetic field. We predicted expected radio fluxes for the two annihilation channels: ! b b and ! þ . We the...

We present a comprehensive study of star-forming (SF) regions in the nearest large spiral galaxy M31. We use GALEX far-UV (1344-1786 Å, FUV) and nearUV (1771-2831 Å, NUV) imaging to detect young massive stars and trace the recent star formation across the galaxy. The FUV and NUV flux measurements of the SF regions, combined with ground-based data for estimating the reddening by interstellar dus...

Recent progress in constraining the massive accretions (>1:10) experienced by Milky Way (MW) and Andromeda galaxy (M31) offers an opportunity to understand dwarf population of Local Group. Using zoom-in dark matter-only simulations MW-mass haloes concentrating on subhaloes that are thought be capable hosting galaxies, we demonstrate infall a progenitor is accompanied with accretion destruction ...

We present new interferometric CO(1-0) and single-dish CO(3-2) observations of the central parts of D478, a large (> 200 pc) dark dust cloud located in a quiescent region of the inner disk of M31 where single-dish CO(1-0) and CO(2-1) observations were previously obtained. Only a small fraction (< 15%) of the CO(1-0) flux previously detected in this region with the single-dish telescope is recor...

The deepest X-ray images of M31, obtained with XMM-Newton, are examined to derive spectral and statistical properties of the population of the softest X-ray sources. Classifying supersoft X-ray sources (SSS) with criteria based on the same hardness ratios defined for recent Chandra observations, a quarter of the selected SSS turn out to be supernova remnants (SNR). Another quarter of SSS are sp...

We report on luminous supersoft X-ray sources (SSSs) in M31. In a survey which was most sensitive to soft sources in four 8×8 regions covered by Chandra’s ACIS-S S3 CCD, we find 33 SSSs that appear to belong to M31. Two of these were first identified as SSSs through ROSAT observations. Two SSSs may be identified with symbiotics, and 2 with supernova remnants. SSSs in the disk are clustered near...