Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Two new confirmed massive relic galaxies: red nuggets in the present-day
  Universe   We confirm two new local massive relic galaxies, i.e. untouched survivors of
the early universe massive population: Mrk1216 and PGC032873. Both show early
and peaked formation events within very short timescales (<1 Gyr) and thus old
mean mass-weighted ages (~13 Gyr). Their star formation histories remain
virtually unchanged out to several effective radii, even when considering the
steeper IMF values inferred out to ~3 effective radii. Their morphologies,
kinematics and density profiles are like those found in the z>2 massive
population, setting them apart of the typical z~0 massive early-type galaxies.
We find that there seems to exist a "degree of relic" that is related on how
far into the path to become one of these typical z~0 massive galaxies the
compact relic has undergone. This path is partly dictated by the environment
the galaxy lives in. For galaxies in rich environments, such as the previously
reported relic galaxy NGC1277, the most extreme properties (e.g. sizes, short
formation timescales, larger super-massive black holes) are expected, while
lower density environments will have galaxies with delayed and/or extended star
formations, slightly larger sizes and not that extreme black hole masses. The
confirmation of 3 relic galaxies up to a distance of 106Mpc implies a lower
limit in the number density of these red nuggets in the local universe of
6x10^{-7} Mpc^{3}, which is within the theoretical expectations.

22
The categories of this paper are: chao-dyn
1
The categories of this paper are: cs
13
The categories of this paper are: quant-ph
8
The categories of this paper are: hep-ex
3
The categories of this paper are: physics
35
The categories of this paper are: mtrl-th
18
The categories of this paper are: econ
32
The categories of this paper are: atom-ph
27
The categories of this paper are: comp-gas
5
The categories of this paper are: gr-qc
19
The categories of this paper are: eess
12
The categories of this paper are: nucl-th
33
The categories of this paper are: plasm-ph
25
The categories of this paper are: patt-sol
2
The categories of this paper are: math
7
The categories of this paper are: hep-th