Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Spectroscopic characterisation of the stellar content of ultra diffuse
  galaxies   Understanding the peculiar properties of Ultra Diffuse Galaxies (UDGs) via
spectroscopic analysis is a challenging task requiring very deep observations
and exquisite data reduction. In this work we perform one of the most complete
characterisations of the stellar component of UDGs to date using deep optical
spectroscopic data from OSIRIS at GTC. We measure radial and rotation
velocities, star formation histories (SFH) and mean population parameters, such
as ages and metallicities, for a sample of five UDG candidates in the Coma
cluster. From the radial velocities, we confirm the Coma membership of these
galaxies. We find that their rotation properties, if detected at all, are
compatible with dwarf-like galaxies. The SFHs of the UDG are dominated by old
(~ 7 Gyr), metal-poor ([M/H] ~ -1.1) and alpha-enhanced ([Mg/Fe] ~ 0.4)
populations followed by a smooth or episodic decline which halted ~ 2 Gyr ago,
possibly a sign of cluster-induced quenching. We find no obvious correlation
between individual SFH shapes and any UDG morphological properties. The
recovered stellar properties for UDGs are similar to those found for DDO44, a
local UDG analogue resolved into stars. We conclude that the UDGs in our sample
are extended dwarfs whose properties are likely the outcome of both internal
processes, such as bursty SFHs and/or high-spin haloes, as well as
environmental effects within the Coma cluster.

21
The categories of this paper are: adap-org
9
The categories of this paper are: nlin
33
The categories of this paper are: plasm-ph
27
The categories of this paper are: comp-gas
1
The categories of this paper are: cs
35
The categories of this paper are: mtrl-th
10
The categories of this paper are: q-bio
29
The categories of this paper are: funct-an
0
The categories of this paper are: hep-ph
18
The categories of this paper are: econ
17
The categories of this paper are: q-fin
30
The categories of this paper are: q-alg
31
The categories of this paper are: ao-sci
5
The categories of this paper are: gr-qc
11
The categories of this paper are: hep-lat
28
The categories of this paper are: alg-geom