J/ApJ/772/13 VLBI observations of 3C 279 at 230GHz (Lu+, 2013)
Fine-scale structure of the quasar 3C 279 measured with 1.3mm very long
baseline interferometry.
Lu R.-S., Fish V.L., Akiyama K., Doeleman S.S., Algaba J.C., Bower G.C.,
Brinkerink C., Chamberlin R., Crew G., Cappallo R.J., Dexter M., Freund R.,
Friberg P., Gurwell M.A., Ho P.T.P., Honma M., Inoue M., Jorstad S.G.,
Krichbaum T.P., Loinard L., MacMahon D., Marrone D.P., Marscher A.P.,
Moran J.M., Plambeck R., Pradel N., Primiani R., Tilanus R.P.J., Titus M.,
Weintroub J., Wright M., Young K.H., Ziurys L.M.
<Astrophys. J., 772, 13 (2013)>
=2013ApJ...772...13L 2013ApJ...772...13L
ADC_Keywords: QSOs ; Millimetric/submm sources ; Interferometry
Keywords: galaxies: active; galaxies: jets; quasars: individual: 3C 279;
radio continuum: galaxies
Abstract:
We report results from five day very long baseline interferometry
(VLBI) observations of the well-known quasar 3C 279 at 1.3mm (230GHz)
in 2011. The measured nonzero closure phases on triangles including
stations in Arizona, California, and Hawaii indicate that the source
structure is spatially resolved. We find an unusual inner jet
direction at scales of ∼1pc extending along the northwest-southeast
direction (P.A.=127°±3°), as opposed to other (previously)
reported measurements on scales of a few parsecs showing inner jet
direction extending to the southwest. The 1.3mm structure corresponds
closely with that observed in the central region of quasi-simultaneous
super-resolution Very Long Baseline Array images at 7mm. The closure
phase changed significantly on the last day when compared with the
rest of observations, indicating that the inner jet structure may be
variable on daily timescales. The observed new direction of the inner
jet shows inconsistency with the prediction of a class of jet
precession models. Our observations indicate a brightness temperature
of ∼8x1010K in the 1.3mm core, much lower than that at centimeter
wavelengths. Observations with better uv coverage and sensitivity in
the coming years will allow the discrimination between different
structure models and will provide direct images of the inner regions
of the jet with 20-30µas (5-7 light months) resolution.
Description:
An ensemble of sources, including 3C 279, was observed with the Event
Horizon Telescope (EHT) during the nights of 2011 March 29 and 31 and
2011 April 1, 2, and 4 (days 88, 90, 91, 92, and 94). Left circular
polarization was observed at all sites. Two 480MHz bandwidths were
centered at 229.089 and 229.601GHz (referred to as the low and high
bands, respectively).
Objects:
----------------------------------------------------
RA (ICRS) DE Designation(s)
----------------------------------------------------
12 56 11.17 -05 47 21.5 3C 279 = QSO B1253-055
----------------------------------------------------
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 54 446 Gain-corrected visibility amplitudes of 3C 279
table3.dat 37 410 Closure phases of 3C 279
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See also:
VIII/85 : SPECFIND V2.0 Catalog of radio continuum spectra (Vollmer+ 2009)
J/AJ/147/143 : MOJAVE. XI. Spectral distributions (Hovatta+, 2014)
J/A+A/566/A59 : 3.5 & 1.3mm polarimetric survey of AGNs (Agudo+, 2014)
J/other/Sci/338.355 : 1.3mm VLBI detections of M87 (Doeleman+, 2012)
J/AJ/144/105 : MOJAVE. VIII. Faraday rotation in AGN jets. (Hovatta+, 2012)
J/ApJ/754/23 : Blazar submm + γ-ray luminosities (Leon-Tavares+, 2012)
J/ApJ/747/63 : 7mm VLBA observations of BL Lac object OJ287 (Agudo+, 2012)
J/ApJ/727/L36 : 1.3mm VLBI observations of Sagittarius A* (Fish+, 2011)
J/MNRAS/418/2260 : VLBI obs. of NRAO 530 at 22, 43 and 86GHz (Lu+, 2011)
J/ApJ/710/764 : Extended radio emission in MOJAVE blazars (Kharb+, 2010)
J/ApJ/707/L56 : VLBI and bright Fermi/LAT sources (Kovalev, 2009)
J/AJ/136/159 : Global 86GHz VLBI survey of compact radio sources (Lee+, 2008)
J/AJ/134/799 : Multiwaveband polarimetry of 15 AGN (Jorstad+, 2007)
J/AJ/133/2866 : 2001-02 opt. variability of blazar 3C 279 (Kartaltepe+, 2007)
J/AJ/130/1418 : AGN jet kinematics (Jorstad+, 2005)
J/A+A/409/857 : Optical polarization of 3C 279 (Andruchow+, 2003)
J/A+A/376/1123 : Bright southern sub-mm sources (Adraou+, 2001)
J/A+A/375/661 : Stability of VLBI reference frame (Gontier+, 2001)
J/ApJ/522/846 : Optical monitoring of GeV loud blazars (Xie+, 1999)
J/A+AS/122/271 : mm-monitoring of radio sources IV. (Reuter+ 1997)
http://www.bu.edu/blazars/VLBAproject.html : Boston University Blazar Group
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 "YYYY-DDD" Obs.date [88/94] Observation date (2011-Mar29 to Apr04)
10- 11 I2 h Obs.h Hour of the observation
13- 14 I2 min Obs.m Minute of the observation
16- 18 A3 --- Code Baseline code (G1)
20- 28 F9.3 --- u [-3402/0.05] The u visibility in
units of Mλ
30- 38 F9.3 --- v [-1360/344] The v visibility in
units of Mλ
40- 44 F5.2 Jy Flux [0.3/13.9] Measured flux density at 1.3mm
46- 49 F4.2 Jy e_Flux [0.03/0.6] The 1σ error in Flux
51- 54 A4 --- Band Band used: "high" (229.601GHz) or
"low" (229.089GHz)
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 "YYYY-DDD" Obs.date [88/94] Observation date (2011-Mar29 to Apr04)
10- 11 I2 h Obs.h Observation (hour)
13- 14 I2 min Obs.m Date of the observation
16- 20 A5 --- Code Triangle code (G1)
22- 27 F6.1 deg CPhase [-175/18] Closure phase
29- 32 F4.1 deg e_CPhase [0.7/31] The 1σ error in CPhase
34- 37 A4 --- Band Band used: "high" (229.601GHz) or
"low" (229.089GHz)
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Globale notes:
Note (G1): Code as follows:
C = A single 10.4-m CARMA antenna (C4).
D = A single 10.4-m CARMA antenna (C1) using a DBE1 backend.
F = The phased sum of seven CARMA antennas.
J = The James Clerk Maxwell Telescope (JCMT), using a DBE1 backend.
O = The Caltech Submillimeter Observatory (CSO), using a DBE1 backend.
P = The phased sum of seven SMA antennas plus either the CSO (day 88)
or the JCMT (days 90-94).
S = The Arizona Radio Observatory Submillimeter Telescope (SMT)
on Mount Graham.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 27-Jan-2015