MULTIWAVELENGTH CONSTRAINTS ON PULSAR POPULATIONS IN THE GALACTIC CENTER

Journal Article · Tue Jul 10 04:00:00 EDT 2012 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/753/2/108· OSTI ID:22039423

Wharton, R S; Chatterjee, S; Cordes, J M ^[1]; Deneva, J S ^[2]; Lazio, T J. W., ^[3]

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1. Department of Astronomy, Cornell University, Ithaca, NY 14853 (United States)
2. Arecibo Observatory, HC3 Box 53995, Arecibo, PR 00612 (Puerto Rico)
3. Jet Propulsion Laboratory, California Institute of Technology, M/S 138-308, 4800 Oak Grove Dr., Pasadena, CA 91109 (United States)

The detection of radio pulsars within the central few parsecs of the Galaxy would provide a unique probe of the gravitational and magneto-ionic environments in the Galactic center (GC) and, if close enough to Sgr A*, precise tests of general relativity in the strong-field regime. While it is difficult to find pulsars at radio wavelengths because of interstellar scattering, the payoff from detailed timing of pulsars in the GC warrants a concerted effort. To motivate pulsar surveys and help define search parameters for them, we constrain the pulsar number and spatial distribution using a wide range of multiwavelength measurements. These include the five known radio pulsars within 15' of Sgr A*, non-detections in high-frequency pulsar surveys of the central parsec, radio and gamma-ray measurements of diffuse emission, a catalog of radio point sources from an imaging survey, infrared observations of massive star populations in the central few parsecs, candidate pulsar wind nebulae in the inner 20 pc, and estimates of the core-collapse supernova rate based on X-ray measurements. We find that under current observational constraints, the inner parsec of the Galaxy could harbor as many as {approx}10{sup 3} active radio pulsars that are beamed toward Earth. Such a large population would distort the low-frequency measurements of both the intrinsic spectrum of Sgr A* and the free-free absorption along the line of sight of Sgr A*.

• OSTI ID: 22039423
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 753; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ABSORPTION
ASTROPHYSICS
CATALOGS
DETECTION
FREQUENCY MEASUREMENT
GALAXIES
GAMMA ASTRONOMY
GAMMA RADIATION
GAMMA SPECTRA
GENERAL RELATIVITY THEORY
GRAVITATIONAL COLLAPSE
NEBULAE
POINT SOURCES
PULSARS
RADIOWAVE RADIATION
SPATIAL DISTRIBUTION
STARS
X RADIATION