GMRT DISCOVERY OF PSR J1544+4937: AN ECLIPSING BLACK-WIDOW PULSAR IDENTIFIED WITH A
                    <i>FERMI</i>
                    -LAT SOURCE

Bhattacharyya, Bhaswati; Roy, Jayanta; Ray, Paul S.; Gupta, Yashwant; Bhattacharya, Dipankar; Romani, Roger W.; Ransom, S. M.; Ferrara, E. C.; Wolff, M. T.; Camilo, F.; Cognard, I.; Harding, A. K.; Hartog, P. R. den; Johnston, S.; Keith, Michael; Kerr, M.; Michelson, P. F.; Parkinson, P. M. Saz; Wood, D. L.; Wood, K. S.

doi:10.1088/2041-8205/773/1/l12

Cited by 68 publications

(79 citation statements)

References 28 publications

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“…HE pulsations have been detected from two extremely luminous MSPs in globular clusters (Freire et al 2011;Wu et al 2013;Johnson et al 2013). The population of known radio MSPs in the Galactic field 15 has been increased by ∼50% through follow-up searches of unassociated LAT sources with pulsar-like characteristics (e.g., Ransom et al 2011;Cognard et al 2011;Keith et al 2011;Ray et al 2012;Barr et al 2013;Bhattacharyya et al 2013), suggesting that MSPs are generally gamma-ray emitters. Of these new radio MSPs, over 75% are in binaries and 11 are "black-widow" systems (with extremely low-mass companions thought to have been ablated by the pulsar wind; see Roberts 2011, for a review), further supporting the recycling scenario.…”

Section: Introductionmentioning

confidence: 99%

Constraints on the Emission Geometries and Spin Evolution of Gamma-Ray Millisecond Pulsars

Johnson

Venter

Harding

et al. 2014

ApJS

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102

157

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Millisecond pulsars (MSPs) are a growing class of gamma-ray emitters. Pulsed gamma-ray signals have been detected from more than 40 MSPs with the Fermi Large Area Telescope (LAT). The wider radio beams and more compact magnetospheres of MSPs enable studies of emission geometries over a broader range of phase space than non-recycled radio-loud gamma-ray pulsars. We have modeled the gamma-ray light curves of 40 LAT-detected MSPs using geometric emission models assuming a vacuum retarded-dipole magnetic field. We modeled the radio profiles using a single-altitude hollow-cone beam, with a core component when indicated by polarimetry; however, for MSPs with gamma-ray and radio light curve peaks occurring at nearly the same rotational phase, we assume that the radio emission is co-located with the gamma rays and caustic in nature. The best-fit parameters and confidence intervals are determined using a maximum likelihood technique. We divide the light curves into three model classes, with gamma-ray peaks trailing (Class I), aligned (Class II), or leading (Class III) the radio peaks. Outer gap and slot gap (two-pole caustic) models best fit roughly equal numbers of Class I and II, while Class III are exclusively fit with pair-starved polar cap models. Distinguishing between the model classes based on typical derived parameters is difficult. We explore the evolution of the magnetic inclination angle with period and spin-down power, finding possible correlations. While the presence of significant off-peak emission can often be used as a discriminator between outer gap and slot gap models, a hybrid model may be needed.

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Section: Introductionmentioning

confidence: 99%

Constraints on the Emission Geometries and Spin Evolution of Gamma-Ray Millisecond Pulsars

Johnson

Venter

Harding

et al. 2014

ApJS

Self Cite

102

157

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“…The majority of the detected gamma-ray pulsars were first found in radio, discovered from either radio pulsar surveys or targeted radio observations of unassociated LAT sources (i.e., sources with no obvious counterparts at other wavelengths; see, e.g., Cognard et al 2011;Keith et al 2011;Ransom et al 2011;Camilo et al 2012Camilo et al , 2015Guillemot et al 2012a;Kerr et al 2012;Barr et al 2013;Bhattacharyya et al 2013;Cromartie et al 2016). However, a substantial fraction of the gamma-ray pulsars have been discovered by direct, blind searches of the LAT data (e.g., Abdo et al 2009;Saz Parkinson et al 2010;Pletsch et al 2012a;Clark et al 2015).…”

Section: Introductionmentioning

confidence: 99%

The Einstein@Home Gamma-ray Pulsar Survey. II. Source Selection, Spectral Analysis, and Multiwavelength Follow-up

Clark

Pletsch

et al. 2018

ApJ

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We report on the analysis of 13 gamma-ray pulsars discovered in the Einstein@Home blind search survey using Fermi Large Area Telescope (LAT) Pass 8 data. The 13 new gamma-ray pulsars were discovered by searching 118 unassociated LAT sources from the third LAT source catalog (3FGL), selected using the Gaussian Mixture Model machine-learning algorithm on the basis of their gamma-ray emission properties being suggestive of pulsar magnetospheric emission. The new gamma-ray pulsars have pulse profiles and spectral properties similar to those of previously detected young gamma-ray pulsars. Follow-up radio observations have revealed faint radio pulsations from two of the newly discovered pulsars and enabled us to derive upper limits on the radio emission from the others, demonstrating that they are likely radio-quiet gamma-ray pulsars. We also present results from modeling the gamma-ray pulse profiles and radio profiles, if available, using different geometric emission models of pulsars. The high discovery rate of this survey, despite the increasing difficulty of blind pulsar searches in gamma rays, suggests that new systematic surveys such as presented in this article should be continued when new LAT source catalogs become available.

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“…Ransom et al 2011;Keith et al 2011;Bhattacharyya et al 2013;Camilo et al 2015). One of the interesting results from the Fermi LAT is that 70 out of 72 new pulsars are MSPs in the Galactic disk (those outside globular clusters), and 54 of them are already confirmed as gamma-ray emitters (the remaining ones will likely be proven so with longer timing).…”

Section: The Pulsar Search Consortium (Psc)mentioning

confidence: 99%

“…However, from the more recent searches, some bright radio MSPs were found in fainter Fermi unassociated sources (e.g. Bhattacharyya et al 2013). These detections suggest that there may be no, or only weak correlations between the flux of the pulsars and the γ-ray sources.…”

Section: Radio and γ-Ray Flux Densitiesmentioning

confidence: 99%

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Searching for New Millisecond Pulsars with the GBT in Fermi Unassociated Sources

Sanpa-arsa¹

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The launch of the Fermi satellite in 2008 revolutionized γ-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 thesis, 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, γ-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 γ-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.

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GMRT DISCOVERY OF PSR J1544+4937: AN ECLIPSING BLACK-WIDOW PULSAR IDENTIFIED WITH A FERMI -LAT SOURCE

Cited by 68 publications

References 28 publications

Constraints on the Emission Geometries and Spin Evolution of Gamma-Ray Millisecond Pulsars

Constraints on the Emission Geometries and Spin Evolution of Gamma-Ray Millisecond Pulsars

The Einstein@Home Gamma-ray Pulsar Survey. II. Source Selection, Spectral Analysis, and Multiwavelength Follow-up

Searching for New Millisecond Pulsars with the GBT in Fermi Unassociated Sources

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