A HIGH-FREQUENCY SEARCH FOR PULSARS WITHIN THE CENTRAL PARSEC OF Sgr A*

Journal Article · Tue Jun 01 04:00:00 EDT 2010 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/715/2/939· OSTI ID:21450928

Macquart, J -P ^[1]; Kanekar, N; Frail, D A ^[2]

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1. Department of Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States)
2. National Radio Astronomy Observatory, 1003 Lopezville Road, Socorro, NM 87801 (United States)

We report results from a deep high-frequency search for pulsars within the central parsec of Sgr A* using the Green Bank Telescope. The observing frequency of 15 GHz was chosen to maximize the likelihood of detecting normal pulsars (i.e., with periods of {approx}500 ms and spectral indices of {approx}-1.7) close to Sgr A* that might be used as probes of gravity in the strong-field regime; this is the highest frequency used for such pulsar searches of the Galactic center (GC) to date. No convincing candidate was detected in the survey, with a 10{sigma} detection threshold of {approx}10 {mu}Jy achieved in two separate observing sessions. This survey represents a significant improvement over previous searches for pulsars at the GC and would have detected a significant fraction ({approx}>5%) of the pulsars around Sgr A*, if they had properties similar to those of the known population. Using our best current knowledge of the properties of the Galactic pulsar population and the scattering material toward Sgr A*, we estimate an upper limit of 90 normal pulsars in orbit within the central parsec of Sgr A*.

• OSTI ID: 21450928
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 715; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
COSMIC RADIO SOURCES
FREQUENCY RANGE
GALAXIES
GHZ RANGE
GRAVITATION
ORBITS
PULSARS
TELESCOPES