Speaker
Description
The launch of the Fermi satellite in 2008 revolutionized gamma-ray pulsar astronomy
by enabling the discovery of many new millisecond pulsars (MSPs). The Fermi
Pulsar Search Consortium (PSC) has organized hundreds of radio observations of
pulsar-like Large Area Telescope (LAT) unassociated sources. Over the past seven
years, the PSC has discovered more than 70 new MSPs, compared to the 75 MSPs found in the 25 years prior to Fermi. The National Radio
Astronomy Observatory's Robert C. Byrd Green Bank Telescope (GBT) has played
the key role in the project by discovering almost half (34) of the new MSPs.
In this talk, I present the discovery and analysis of 16 new MSPs, 10 of which were uncovered by me personally.
The pulsars were found in GBT searches within the positional error boxes of 266
Fermi LAT sources, both at high Galactic latitudes and closer to
the Galactic plane. All new pulsars have phase-connected radio timing solutions,
and for 12 of them, gamma-ray pulsations were detected.
Twelve MSPs have Helium white dwarf (He-WD) companions and the other four are in so-called "spider" systems with
compact orbits and non-degenerate companions. We investigated
the relationship between radio and gamma-ray flux densities for all MSPs, confirming that there is almost no correlation between the two. We also investigated the
orbital period vs. companion mass relation for MSPs with He-WD companions
using a simple Monte Carlo technique, and found that the distribution of binary inclination angles is not random but possibly leans towards lower inclinations. For the four MSPs in compact orbits,
we examined flux density variability, as well as their optical light curves. We found that all four MSPs are eclipsing and that two of them exhibit strong diffractive scintillation. Finally, we found optical counterparts for two MSPs, one of which shows ellipsoidal modulations in its light curve, suggesting that the companion is filling its Roche lobe.
