RESOLVING THE INNER JET STRUCTURE OF 1924-292 WITH THE EVENT HORIZON TELESCOPE

Journal Article · Thu Sep 20 00:00:00 EDT 2012 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/757/1/L14· OSTI ID:22078536

Rusen, Lu; Fish, Vincent L; Doeleman, Sheperd S ^[1]; Weintroub, Jonathan; Moran, James M; Primiani, Rurik; Young, Ken H ^[2]; Bower, Geoffrey C; Plambeck, Richard; Wright, Melvyn ^[3]; Freund, Robert; Marrone, Daniel P ^[4]; Friberg, Per; Tilanus, Remo P. J. ^[5]; Ho, Paul T. P.; Inoue, Makoto ^[6]; Honma, Mareki; Oyama, Tomoaki ^[7]; Krichbaum, Thomas P ^[8]; others, and

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1. Massachusetts Institute of Technology, Haystack Observatory, Route 40, Westford, MA 01886 (United States)
2. Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)
3. Department of Astronomy, Radio Astronomy Laboratory, University of California Berkeley, 601 Campbell Hall, Berkeley, CA 94720-3411 (United States)
4. Arizona Radio Observatory, Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721-0065 (United States)
5. James Clerk Maxwell Telescope, Joint Astronomy Centre, 660 North A'ohoku Place, University Park, Hilo, HI 96720 (United States)
6. Institute of Astronomy and Astrophysics, Academia Sinica, P.O. Box 23-141, Taipei 10617, Taiwan (China)
7. National Astronomical Observatory of Japan, Osawa 2-21-1, Mitaka, Tokyo 181-8588 (Japan)
8. Max-Planck-Institut fuer Radioastronomie, Auf dem Huegel 69, D-53121 Bonn (Germany)

We present the first 1.3 mm (230 GHz) very long baseline interferometry model image of an active galactic nucleus (AGN) jet using closure phase techniques with a four-element array. The model image of the quasar 1924-292 was obtained with four telescopes at three observatories: the James Clerk Maxwell Telescope on Mauna Kea in Hawaii, the Arizona Radio Observatory's Submillimeter Telescope in Arizona, and two telescopes of the Combined Array for Research in Millimeter-wave Astronomy in California in 2009 April. With the greatly improved resolution compared with previous observations and robust closure phase measurement, the inner jet structure of 1924-292 was spatially resolved. The inner jet extends to the northwest along a position angle of -53 Degree-Sign at a distance of 0.38 mas from the tentatively identified core, in agreement with the inner jet structure inferred from lower frequencies, and making a position angle difference of {approx}80 Degree-Sign with respect to the centimeter jet. The size of the compact core is 0.15 pc with a brightness temperature of 1.2 Multiplication-Sign 10{sup 11} K. Compared with those measured at lower frequencies, the low brightness temperature may argue in favor of the decelerating jet model or particle-cascade models. The successful measurement of closure phase paves the way for imaging and time resolving Sgr A* and nearby AGNs with the Event Horizon Telescope.

• OSTI ID: 22078536
• Journal Information: Astrophysical Journal Letters, Vol. 757, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
BRIGHTNESS
GALAXIES
GHZ RANGE
IMAGES
INTERFEROMETRY
JET MODEL
QUASARS
RESOLUTION
TELESCOPES