J/ApJ/817/128 Megamaser Cosmology Project. VIII. NGC5765B (Gao+, 2016)
The Megamaser Cosmology Project.
VIII. A geometric distance to NGC 5765b.
Gao F., Braatz J.A., Reid M.J., Lo K.Y., Condon J.J., Henkel C., Kuo C.Y.,
Impellizzeri C.M.V., Pesce D.W., Zhao W.
<Astrophys. J., 817, 128 (2016)>
=2016ApJ...817..128G 2016ApJ...817..128G (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, nearby ; Interferometry ; Masers ; Models
Keywords: cosmological parameters; dark energy; distance scale;
galaxies: individual: NGC 5765b; galaxies: nuclei; masers
Abstract:
As part of the Megamaser Cosmology Project, here we present a new
geometric distance measurement to the megamaser galaxy NGC 5765b.
Through a series of very long baseline interferometry observations, we
have confirmed the water masers trace a thin, sub-parsec Keplerian
disk around the nucleus, implying an enclosed mass of
4.55±0.40x107M☉. Meanwhile, from single-dish monitoring of
the maser spectra over two years, we measured the secular drifts of
maser features near the systemic velocity of the galaxy with rates
between 0.5 and 1.2km/s/yr. Fitting a warped, thin-disk model to these
measurements, we determine a Hubble Constant H0 of
66.0±6.0km/s/Mpc with an angular-diameter distance to NGC 5765b of
126.3±11.6Mpc. Apart from the distance measurement, we also
investigate some physical properties related to the maser disk in NGC
5765b. The high-velocity features are spatially distributed into
several clumps, which may indicate the existence of a spiral density
wave associated with the accretion disk. For the redshifted features,
the envelope defined by the peak maser intensities increases with
radius. The profile of the systemic masers in NGC 5765b is smooth and
shows almost no structural changes over the two years of monitoring
time, which differs from the more variable case of NGC 4258.
Description:
To map the spatial distribution of maser spots in NGC 5765b, we
conducted a series of VLBI observations between 2012 April and 2014
January, with the 10 antennas of the Very Long Baseline Array (VLBA),
augmented by the 100m GBT, the Effelsberg 100m telescope (EB), and the
Karl G. Jansky Very Large Array (VLA).
Objects:
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RA (ICRS) DE Designation(s)
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14 50 51.51 +05 06 52.2 NGC 5765b = NGC 5765B = MCG+01-38-005
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table6.dat 50 192 Input data for the disk fitting program
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See also:
J/ApJS/218/10 : HET Massive Galaxy Survey (HETMGS) (van den Bosch+, 2015)
J/MNRAS/412/1419 : Nearby supernova rates (Leaman+, 2011)
J/ApJ/727/20 : The Megamaser Cosmology Project (MCP). III. (Kuo+, 2011)
J/ApJ/659/1040 : VLBI monitoring of NGC 4258 (Argon+, 2007)
Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
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1- 7 F7.2 km/s Vel [7537.5/9081.3] Maser Recession Velocity
9- 15 F7.4 mas X [-0.7/1.2] Black Hole Position, X
17- 22 F6.4 mas e_X [0.0007/0.03] Uncertainty in X
24- 30 F7.4 mas Y [-1.58/0.92] Black Hole Position, Y
32- 37 F6.4 mas e_Y [0.001/0.07] Uncertainty in Y
39- 44 F6.3 km/s/yr A [-0.6/1.3] Acceleration
46- 50 F5.3 km/s/yr e_A [0.01/0.9] Uncertainty in A
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History:
From electronic version of the journal
References:
Braatz et al. Paper I. 2009ApJ...695..287R 2009ApJ...695..287R
Braatz et al. Paper II. 2010ApJ...718..657B 2010ApJ...718..657B
Kuo et al. Paper III. 2011ApJ...727...20K 2011ApJ...727...20K Cat. J/ApJ/727/20
Reid et al. Paper IV. 2013ApJ...767..154R 2013ApJ...767..154R
Kuo et al. Paper V. 2013ApJ...767..155K 2013ApJ...767..155K
Kuo et al. Paper VI. 2015ApJ...800...26K 2015ApJ...800...26K
Pesce et al. Paper VII. 2015ApJ...810...65P 2015ApJ...810...65P
Gao et al. Paper VIII. 2016ApJ...817..128G 2016ApJ...817..128G This catalog.
Gao et al. Paper IX. 2017ApJ...834...52G 2017ApJ...834...52G Cat. J/ApJ/834/52