The age of the Milky Way inner stellar spheroid from RR Lyrae population synthesis

  title={The age of the Milky Way inner stellar spheroid from RR Lyrae population synthesis},
  author={Alessandro Savino and Andreas Koch and Z. Prudil and Andrea M. Kunder and Radosław Smolec},
  journal={Astronomy \& Astrophysics},
The central kiloparsecs of the Milky Way are known to host an old, spheroidal stellar population, whose spatial and kinematical properties set it apart from the boxy-peanut structure that constitutes most of the central stellar mass. The nature of this spheroidal population, whether it is a small classical bulge, the innermost stellar halo, or a population of disk stars with large initial velocity dispersion, remains unclear. This structure is also a promising candidate to play host to some of… 

The Milky Way's bar and bulge revealed by APOGEE DR16 and Gaia DR2

We investigate the inner regions of the Milky Way with a sample of unprecedented size and coverage thanks to APOGEE DR16 and {\it Gaia} DR2 data. Our inner Galactic sample has more than 24,000 stars

The Hubble Space Telescope Survey of M31 Satellite Galaxies. I. RR Lyrae–based Distances and Refined 3D Geometric Structure

We measure homogeneous distances to M31 and 38 associated stellar systems (−16.8 ≤ M V ≤ −6.0), using time-series observations of RR Lyrae stars taken as part of the Hubble Space Telescope Treasury

An Old, Metal-rich Accreted Stellar Component in the Milky Way Stellar Disk

We study the possibility that the Milky Ways’ cool stellar disk includes mergers with ancient stars. Galaxies are understood to form in a hierarchical manner, where smaller (proto-)galaxies merge

Photometric Metallicity Prediction of Fundamental-mode RR Lyrae Stars in the Gaia Optical and K s Infrared Wave Bands by Deep Learning

RR Lyrae stars are useful chemical tracers thanks to the empirical relationship between their heavy-element abundance and the shape of their light curves. However, the consistent and accurate

Metallicity of Galactic RR Lyrae from Optical and Infrared Light Curves. II. Period–Fourier–Metallicity Relations for First Overtone RR Lyrae

We present new period-ϕ 31-[Fe/H] relations for first-overtone RRL stars (RRc), calibrated over a broad range of metallicities (−2.5 ≲ [Fe/H] ≲ 0.0) using the largest currently available set of

RR Lyrae Variables as Tracers of the Galactic Bulge Kinematic Structure

RR Lyrae stars are recognized as some of the oldest stars in the Universe. In addition, they are some of the few old celestial objects for which distances can be reliably inferred. As such, these

Variable Stars in the Giant Satellite Galaxy Antlia 2

We report 350 pulsating variable stars found in four DECam fields (∼12 deg2) covering the Antlia 2 satellite galaxy. The sample of variables includes 318 RR Lyrae stars and eight anomalous Cepheids

Why We Should Take Interstellar Panspermia Seriously

  • A. Balbi
  • Physics
    Planet Formation and Panspermia
  • 2021

Variable stars in Local Group galaxies – V. The fast and early evolution of the low-mass Eridanus II dSph galaxy

We present a detailed study of the variable star population of Eridanus II (Eri II), an ultra-faint dwarf galaxy that lies close to the Milky Way virial radius. We analyse multi-epoch g, r, i

RR Lyrae Stars in the Newly Discovered Ultra-faint Dwarf Galaxy Centaurus I

We report the detection of three RR Lyrae (RRL) stars (two RRc and one RRab) in the ultra-faint dwarf (UFD) galaxy Centaurus I (Cen I) and two Milky Way (MW) δ Scuti/SX Phoenicis stars based on



Iron exacerbates aniline-associated splenic toxicity.

The increased toxicity, as evident from greater oxidative stress and morphological changes in the AH + IR group, suggests that iron potentiates the splenic toxicity of aniline.

For-profit hospital ownership status and use of brachytherapy after breast-conserving surgery.


Results are presented of a search for RR Lyrae variables in the SMC clusters NGC 121, Lindsay 1, Kron 3, Kron 7, and Kron 44. The techniques used rediscovered the four RR Lyraes in NGC 121, but no

The Chemical Composition of the Galactic Bulge and Implications for its Evolution

  • A. McWilliam
  • Physics
    Publications of the Astronomical Society of Australia
  • 2016
Abstract At a bulge latitude of b = −4°, the average [Fe/H] and [Mg/H] values are +0.06 and +0.17 dex, roughly 0.2 and 0.7 dex higher than the local thin and thick disk values, respectively,

Horizontal-Branch Models and the Second-Parameter Effect. III. The Impact of Mass Loss on the Red Giant Branch and the Case of M5 and Palomar 4/Eridanus

Deep Hubble Space Telescope (HST) photometry has recently been presented for the outer halo globular clusters Palomar 4 and Eridanus. The new high-precision color-magnitude diagrams obtained for

The Bulge Radial Velocity Assay for RR Lyrae Stars (BRAVA-RR) DR2: A Bimodal Bulge?

The radial velocities of 2768 fundamental-mode RR Lyrae stars (RRLs) toward the southern Galactic bulge are presented, spanning the southern bulge from −8° < l < + 8° and −3° < b < −6°. Distances

Evidence for Galactic disc RR Lyrae stars in the solar neighbourhood

We present a kinematical study of 314 RR Lyrae stars in the solar neighbourhood using the publicly available photometric, spectroscopic, and Gaia DR2 astrometric data to explore their distribution

Local RR Lyrae stars: native and alien

Measurements of [Fe/H] and radial velocity are presented for 89 RR Lyrae (RRL) candidates within 6 kpc of the Sun. After the removal of two suspected non-RRLs, these stars were added to an existing

The Nature of Young RR Lyrae Field Stars with Solar Metallicity

Based on published parameters of their atmospheres, the masses of 100 RR Lyrae variables (lyrids) in the field are determined using evolutionary tracks from the Dartmouth data base and the properties

The Pristine Inner Galaxy Survey (PIGS) I: tracing the kinematics of metal-poor stars in the Galactic bulge

Our Galaxy is known to contain a central boxy/peanut-shaped bulge, yet the importance of a classical, pressure-supported component within the central part of the Milky Way is still being debated.