Eight γ-Ray Pulsars Discovered In Blind Frequency Searches Of Fermi Lat Data

Journal Article · Fri Nov 19 00:00:00 EST 2010 · The Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/725/1/571· OSTI ID:1357511

Saz Parkinson, P. M. ^[1]; Dormody, M. ^[1]; Ziegler, M. ^[1]; Ray, P. S. ^[2]; Abdo, A. A. ^[3]; Ballet, J. ^[4]; Baring, M. G. ^[5]; Belfiore, A. ^[6]; Burnett, T. H. ^[7]; Caliandro, G. A. ^[8]; Camilo, F. ^[9]; Caraveo, P. A. ^[10]; de Luca, A. ^[11]; Ferrara, E. C. ^[12]; Freire, P. C. C. ^[13]; Grove, J. E. ^[2]; Gwon, C. ^[2]; Harding, A. K. ^[12]; Johnson, R. P. ^[1]; Johnson, T. J. ^[14] ; Johnston, S. ^[15]; Keith, M. ^[15]; Kerr, M. ^[7]; Knödlseder, J. ^[16]; Makeev, A. ^[17]; Marelli, M. ^[18]; Michelson, P. F. ^[19]; Parent, D. ^[17]; Ransom, S. M. ^[20]; Reimer, O. ^[21]; Romani, R. W. ^[19]; Smith, D. A. ^[22]; Thompson, D. J. ^[12]; Watters, K. ^[19]; Weltevrede, P. ^[23]; Wolff, M. T. ^[2]; Wood, K. S. ^[2]

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1. Univ. of California, Santa Cruz, CA (United States)
2. Naval Research Lab. (NRL), Washington, DC (United States)
3. Naval Research Lab. (NRL), Washington, DC (United States); National Academy of Sciences, Washington, DC (United States)
4. Univ. Paris Diderot, Gif sur Yvette (France)
5. Rice Univ., Houston, TX (United States)
6. Univ. of California, Santa Cruz, CA (United States); Univ. of Pavia (Italy); Istituto Nazionale di Astrofisica (INAF), Milano (Italy)
7. Univ. of Washington, Seattle, WA (United States)
8. Inst. de Ciencies de l'Espai, Barcelona (Spain)
9. Columbia Univ., New York, NY (United States). Columbia Astrophysics Lab.
10. Istituto Nazionale di Astrofisica (INAF), Milano (Italy)
11. Istituto Universitario di Studi Superiori (IUSS), Pavia (Italy)
12. NASA Goddard Space Flight Center (GSFC), Greenbelt, MD (United States)
13. Max Planck Inst. for Radioastronomy, Bonn (Germany)
14. NASA Goddard Space Flight Center (GSFC), Greenbelt, MD (United States); Univ. of Maryland, College Park, MD (United States)
15. Australia Telescope National Facility, Epping NSW (Australia)
16. Centre d'Étude Spatiale des Rayonnements, Toulouse (France)
17. Naval Research Lab. (NRL), Washington, DC (United States); George Mason Univ., Fairfax, VA (United States)
18. Istituto Nazionale di Astrofisica (INAF), Milano (Italy); Univ. degli Studi dell'Insubria, Varese (Italy)
19. SLAC National Accelerator Lab., Menlo Park, CA (United States)
20. National Radio Astronomy Observatory (NRAO), Charlottesville, VA (United States)
21. SLAC National Accelerator Lab., Menlo Park, CA (United States); Leopold-Franzens-Univ., Innsbruck (Austria)
22. Univ. of Bordeaux, Gradignan (France). Centre d'etudes Nucleaires Bordeaux Gradignan; CNRS/IN2P3 (France)
23. Univ. of Manchester (United Kingdom)

We report the discovery of eight γ-ray pulsars in blind frequency searches of ~650 source positions using the Large Area Telescope (LAT), on board the Fermi Gamma-ray Space Telescope. We present the timing models, light curves, and detailed spectral parameters of the new pulsars. PSRs J1023-5746, J1044-5737, J1413-5205, J1429-5911, and J1954+2836 are young (τ c < 100 kyr), energetic ($$\dot{E} \gtrsim 10^{36}$$ erg s–1), and located within the Galactic plane (|b| < 3°). The remaining three pulsars, PSRs J1846+0919, J1957+5033, and J2055+25, are less energetic, and located off the plane. Five pulsars are associated with sources included in the Fermi-LAT bright γ-ray source list, but only one, PSR J1413–6205, is clearly associated with an EGRET source. PSR J1023–5746 has the smallest characteristic age (τ c = 4.6 kyr) and is the most energetic ($$\dot{E} = 1.1 \times 10^{37}$$ erg s–1) of all γ-ray pulsars discovered so far in blind searches. By analyzing >100 ks of publicly available archival Chandra X-ray data, we have identified the likely counterpart of PSR J1023–5746 as a faint, highly absorbed source, CXOU J102302.8-574606. The large X-ray absorption indicates that this could be among the most distant γ-ray pulsars detected so far. PSR J1023–5746 is positionally coincident with the TeV source HESS J1023–575, located near the young stellar cluster Westerlund 2, while PSR J1954+2836 is coincident with a 4.3σ excess reported by Milagro at a median energy of 35 TeV. PSRs J1957+5033 and J2055+25 have the largest characteristic ages (τ c ~ 1 Myr) and are the least energetic ($$\dot{E} \sim 5\times 10^{33}$$ erg s–1) of the newly discovered pulsars. We used recent XMM observations to identify the counterpart of PSR J2055+25 as XMMU J205549.4+253959. Deep radio follow-up observations of the eight pulsars resulted in no detections of pulsations and upper limits comparable to the faintest known radio pulsars, indicating that these pulsars can be included among the growing population of radio-quiet pulsars in our Galaxy being uncovered by the LAT, and currently numbering more than 20.

• Research Organization: SLAC National Accelerator Lab., Menlo Park, CA (United States)
• Sponsoring Organization: USDOE
• Grant/Contract Number: AC02-76SF00515
• OSTI ID: 1357511
• Journal Information: The Astrophysical Journal, Vol. 725, Issue 1; ISSN 0004-637X
• Publisher: Institute of Physics (IOP)
• Country of Publication: United States
• Language: English

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