Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Mrk 1419 - a new distance determination   Water vapor megamasers from the center of active galaxies provide a powerful
tool to trace accretion disks at sub-parsec resolution and, through an entirely
geometrical method, measure direct distances to galaxies up to 200 Mpc. The
Megamaser Cosmology Project (MCP) is formed by a team of astronomers with the
aim of identifying new maser systems, and mapping their emission at high
angular resolution to determine their distance. Two types of observations are
necessary to measure a distance: single-dish monitoring to measure the
acceleration of gas in the disk, and sensitive VLBI imaging to measure the
angular size of the disk, measure the rotation curve, and model radial
displacement of the maser feature. The ultimate goal of the MCP is to make a
precise measurement of H0 by measuring such distances to at least 10 maser
galaxies in the Hubble flow. We present here the preliminary results from a new
maser system, Mrk 1419. Through a model of the rotation from the systemic
masers assuming a narrow ring, and combining these results with the
acceleration measurement from the Green Bank Telescope, we determine a distance
to Mrk 1419 of 81\pm10 Mpc. Given that the disk shows a significant warp that
may not be entirely traced by our current observations, more sensitive
observations and more sophisticated disk modeling will be essential to improve
our distance estimation to this galaxy.

21
The categories of this paper are: adap-org
31
The categories of this paper are: ao-sci
28
The categories of this paper are: alg-geom
14
The categories of this paper are: math-ph
10
The categories of this paper are: q-bio
12
The categories of this paper are: nucl-th
11
The categories of this paper are: hep-lat
18
The categories of this paper are: econ
22
The categories of this paper are: chao-dyn
0
The categories of this paper are: hep-ph
8
The categories of this paper are: hep-ex
33
The categories of this paper are: plasm-ph
25
The categories of this paper are: patt-sol
26
The categories of this paper are: bayes-an
35
The categories of this paper are: mtrl-th
17
The categories of this paper are: q-fin