Abstract

We present results of a 40-hour survey of the nearby galaxy M31 for giant radio pulses (GRPs) from radio pulsars using the Green Bank Radio telescope (GBT) in the 300 MHz to 400 MHz band. We note that GRPs from known pulsars in the Milky Way or its nearest companion galaxies, the Magellanic clouds, if relocated to M31, would not be detectable with the GBT in the 300 MHz to 400 MHz band. However, the brightest GRPs from a pulsar in M31, like the Crab pulsar B0531+21, are within a factor of 2 of detectability. Our observations cover a projected surface area of 8000 kpc2 at the distance of M31 including the Galactic bulge and most of the stellar disk. M32 is included, but M110 is not. The dwarf galaxy AND III is partially sampled. We analyze sources of interference including meteor head scattering of military and civilian air traffic control channels into the GBT beam during the 2015 Orionid and Taurid meteor showers coincident with our observing time. We report our methods for interference mitigation and methods for visualizing and exploring the data. Dispersion measures (DM) from 30 pc cm−3 to 500 pc cm−3 were searched using the PRESTO library. There are no detections of pulses which repeated regularly during our 2.3-minute individual pointings. However, there are detections of candidate events which are either isolated in time or have one or two repetitions during our observations. These candidates have dispersion measures which are plausible values for M31. We detect a candidate event which has a dispersion measure of 54.7 pc cm−3 which is the value of the 6 events reported by [Rubio-Herrera et al., 2013]. Our observations are consistent with a search for pulses in M31 with LOFAR. If any of our candidates are real events, there must be a population of objects in M31 which are more luminous than the Crab pulsar and which emit very luminous pulses intermittently.

Library of Congress Subject Headings

Pulsars--Detection; Magnetars; Andromeda Galaxy

Publication Date

8-2023

Document Type

Dissertation

Student Type

Graduate

Degree Name

Astrophysical Sciences and Technology (Ph.D.)

Department, Program, or Center

School of Physics and Astronomy (COS)

Advisor

Jennifer Schneider

Advisor/Committee Member

Zoran Ninkov

Advisor/Committee Member

Samar Safi-Harb

Campus

RIT – Main Campus

Plan Codes

ASTP-PHD

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