DISCOVERY OF LOW DM FAST RADIO TRANSIENTS: GEMINGA PULSAR CAUGHT IN THE ACT

Journal Article · Sun Dec 20 04:00:00 EST 2015 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/815/2/126· OSTI ID:22521754

Maan, Yogesh ^[1]

---

1. National Centre for Radio Astrophysics, Pune 411007 (India)

We report the discovery of several energetic radio bursts at 34 MHz, using the Gauribidanur radio telescope. The radio bursts exhibit two important properties associated with the propagation of astronomical signals through the interstellar medium: (i) frequency dependent dispersive delays across the observing bandwidth and (ii) Faraday rotation of the plane of linear polarization. These bursts sample a range of dispersion measures (DM; 1.4–3.6 pc cm{sup −3}) and show DM-variation at timescales of the order of a minute. Using groups of bursts having a consistent DM, we show that the bursts have originated from the radio-quiet gamma-ray pulsar Geminga. Detection of these bursts supports the existence of occasional radio emission from Geminga. The rare occurrence of these bursts, and the short timescale variation in their DM (if really caused by the intervening medium or the pulsar magnetosphere), might provide clues as to why the pulsar has not been detected in earlier sensitive searches. We present details of the observations and search procedure used to discover these bursts, a detailed analysis of their properties, and evidences of these bursts being associated with Geminga pulsar, and briefly discuss the possible emission mechanism of these bursts.

• OSTI ID: 22521754
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 815; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
COSMIC RADIO SOURCES
DETECTION
FARADAY EFFECT
FREQUENCY DEPENDENCE
GAMMA RADIATION
MHZ RANGE
PHOTON EMISSION
POLARIZATION
PULSARS
RADIO TELESCOPES
SIGNALS
STELLAR MAGNETOSPHERES
TRANSIENTS
VARIATIONS