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Gamma-ray Emission from Globular Clusters
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 Title & Authors
Gamma-ray Emission from Globular Clusters
Tam, Pak-Hin T.; Hui, Chung Y.; Kong, Albert K. H.;
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Over the last few years, the data obtained using the Large Area Telescope (LAT) aboard the Fermi Gamma-ray Space Telescope has provided new insights on high-energy processes in globular clusters, particularly those involving compact objects such as MilliSecond Pulsars (MSPs). Gamma-ray emission in the 100 MeV to 10 GeV range has been detected from more than a dozen globular clusters in our galaxy, including 47 Tucanae and Terzan 5. Based on a sample of known gammaray globular clusters, the empirical relations between gamma-ray luminosity and properties of globular clusters such as their stellar encounter rate, metallicity, and possible optical and infrared photon energy densities, have been derived. The measured gamma-ray spectra are generally described by a power law with a cut-off at a few gigaelectronvolts. Together with the detection of pulsed γ-rays from two MSPs in two different globular clusters, such spectral signature lends support to the hypothesis that γ-rays from globular clusters represent collective curvature emission from magnetospheres of MSPs in the clusters. Alternative models, involving Inverse-Compton (IC) emission of relativistic electrons that are accelerated close to MSPs or pulsar wind nebula shocks, have also been suggested. Observations at >100 GeV by using Fermi/LAT and atmospheric Cherenkov telescopes such as H.E.S.S.-II, MAGIC-II, VERITAS, and CTA will help to settle some questions unanswered by current data.
gamma-ray observations;clusters;globular;
 Cited by
Abdo AA, Ackermann M, Ajello M, Anderson B, Atwood WB, et al., Detection of 16 Gamma-Ray Pulsars Through Blind Frequency Searches Using the Fermi LAT, Science 325, 840-844 (2009a). crossref(new window)

Abdo AA, Ackermann M, Ajello M, Atwood WB, Axelsson M, et al., Detection of High-Energy Gamma-Ray Emission from the Globular Cluster 47 Tucanae with Fermi, Science 325, 845-848 (2009b). crossref(new window)

Abdo AA, Ackermann M, Ajello M, Atwood WB, Axelsson M, et al., A Population of Gamma-Ray Millisecond Pulsars Seen with the Fermi Large Area Telescope, Science 325, 848-852 (2009c). crossref(new window)

Abdo AA, Ackermann M, Ajello M, Allafort A, Antolini E, et al., Fermi Large Area Telescope First Source Catalog, Astrophys. J. Suppl. Ser. 188, 405-436 (2010a). crossref(new window)

Abdo AA, Ackermann M, Ajello M, Baldini L, Ballet J, et al., A population of gamma-ray emitting globular clusters seen with the Fermi Large Area Telescope, Astron. Astrophys. 524, 75 (2010b). crossref(new window)

Abramowski A, Acero, F, Aharonian F, Akhperjanian AG, Anton G, et al., Very-high-energy gamma-ray emission from the direction of the Galactic globular cluster Terzan 5, Astron. Astrophys. 531, L18 (2011). crossref(new window)

Abramowski A, Acero F, Aharonian F, Akhperjanian AG, Anton G, et al., Search for very-high-energy γ-ray emission from Galactic globular clusters with H.E.S.S., Astron. Astrophys. 551, A26 (2013). crossref(new window)

Acero F, Ackermann M, Ajello M, Albert A, Atwood WB, et al., Fermi Large Area Telescope Third Source Catalog, Astrophys. J. Suppl. Ser. 218, 23-63 (2015). crossref(new window)

Ackermann M, Ajello M, Allafort A, Atwood WB, Baldini L, et al., The First-Fermi LAT Catalog of Sources above 10 GeV, Astrophys. J. Suppl. Ser. 209, 34 (2013). crossref(new window)

Aharonian F, Akhperjanian AG, Anton G, Barres de Almeida U, Bazer-Bachi AR, et al., Astron. Astrophys. 499, 273-277 (2009). crossref(new window)

Alpar MA, Cheng AF, Ruderman MA, Shaham J, A new class of radio pulsars, Nature 300, 728-730 (1982). crossref(new window)

Anderhub H, Antonelli LA, Antoranz P, Backes M, Baixeras C, et al., Search for VHE γ-ray Emission from the Globular Cluster M13 with the Magic Telescope, Astrophys. J. 702, 266-269 (2009). crossref(new window)

Bednarek W, Gamma-rays from millisecond pulsars in Globular Clusters, High-Energy Emission from Pulsars and their Systems, eds. Torres DF, Rea N (Springer Berlin Heidelberg, 2011), 185-205.

Bednarek W, Gamma-rays from electrons accelerated by rotating magnetized white dwarfs in globular clusters, J. Phys. G 39, 065001 (2012). crossref(new window)

Bednarek W, Sitarek J, High-energy γ-rays from globular clusters, Mon. Not. Roy. Astron. Soc. 377, 920-930 (2007). crossref(new window)

Bednarek W, Sobczak T, Misaligned TeV γ-ray sources in the vicinity of globular clusters, Mon. Not. Roy. Astron. Soc. 445, 2842-2847 (2014). crossref(new window)

Bogdanov S, Grindlay JE, Heinke CO, Camilo Fernando, Freire PCC, et al., Chandra X-Ray Observations of 19 Millisecond Pulsars in the Globular Cluster 47 Tucanae, Astrophys. J. 646, 1104-1115 (2006). crossref(new window)

Chen K, Gamma-ray emission from millisecond pulsars in globular clusters, Nature 352, 695-697 (1991). crossref(new window)

Cheng KS, Taam RE, On the Origin of X-Ray Emission from Millisecond Pulsars in 47 Tucanae, Astrophys. J. 598, 1207-1216 (2003). crossref(new window)

Cheng KS, Chernyshov DO, Dogiel VA, Hui CY, Kong AKH, The Origin of Gamma Rays from Globular Clusters, Astrophys. J. 723, 1219-1230 (2010). crossref(new window)

Clapson AC, Domainko W, Jamrozy M, Dyrda M, Eger P, Multiwavelength environment of the Galactic globular cluster Terzan 5, Astron. Astrophys. 532, A47 (2011). crossref(new window)

Clark GW, X-ray binaries in globular clusters, Astrophys. J. 199, L143 (1975). crossref(new window)

Domainko WF, Finding short GRB remnants in globular clusters: the VHE gamma-ray source in Terzan 5, Astron. Astrophys. 533, L5 (2011). crossref(new window)

Domainko WF, Ruffert M, Remnants of compact binary mergers, Adv. Space Res. 41, 518-522 (2008). crossref(new window)

Freire PCC, Abdo AA, Ajello M, Allafort A, Ballet J, et al., Fermi Detection of a Luminous γ-Ray Pulsar in a Globular Cluster, Science 334, 1107-1110 (2011). crossref(new window)

Gendre B, Barret D, Webb N, Discovery of a quiescent neutron star binary in the globular cluster M 13, Astron. Astrophys. 403, L11 (2003). crossref(new window)

Harris WE, A Catalog of Parameters for Globular Clusters in the Milky Way, Astron. J. 112, 1487 (1996). (2010 edition, available from: crossref(new window)

Hui CY, Cheng KS, Taam RE, Dynamical Formation of Millisecond Pulsars in Globular Clusters, Astrophys. J. 714, 1149-1154 (2010). crossref(new window)

Hui CY, Cheng KS, Wang Y, Tam PHT, Kong AKH, et al., The Fundamental Plane of Gamma-ray Globular Clusters, Astrophys. J. 726, 100-106 (2011). crossref(new window)

Ivanova N, Low-Mass X-Ray Binaries and Metallicity Dependence: Story of Failures, Astrophys. J. 636, 979-984 (2006). crossref(new window)

Johnson TJ, Guillemot L, Kerr M, Cognard I, Ray PS, et al., Broadband Pulsations from PSR B1821-24: Implications for Emission Models and the Pulsar Population of M28, Astrophys. J. 778, 106-117 (2013). crossref(new window)

Kabuki S, Enomoto R, Bicknell GV, Clay RW, Edwards PG, et al., CANGAROO III Search for Gamma Rays from Centaurus A and the ω Centauri Region, Astrophys. J. 668, 968-973 (2007). /10.1086/520767 crossref(new window)

Katz JI, Two kinds of stellar collapse, Nature 253, 698-699 (1975). crossref(new window)

Kong AKH, Hui CY, Cheng KS, Fermi Discovery of Gamma-ray Emission from the Globular Cluster Terzan 5, Astrophys. J. Lett. 712, L36 (2010). crossref(new window)

Manandhar RP, Grindlay JE, Thompson DJ, New EGRET/COMPTEL studies of globular clusters, Astron. Astrophys. Suppl. Ser. 120, 255-260 (1996).

Manchester RN, Hobbs GB, Teoh A, Hobbs M, The Australia Telescope National Facility Pulsar Catalogue, Astron. J. 129, 1993-2006 (2005). crossref(new window)

McCutcheon M, for the VERITAS Collaboration, VERITAS Observations of Globular Clusters, in 31st International Cosmic Ray Conference (ICRC), Lodz, Poland, 7-15 Jul 2009.

McLaughlin DE, Anderson J, Meylan G, Gebhardt K, Pryor C, et al., Hubble Space Telescope Proper Motions and Stellar Dynamics in the Core of the Globular Cluster 47 Tucanae, Astrophys. J. Supple. Ser. 166, 249-297 (2006). crossref(new window)

Michelson PF, Bertsch DL, Brazier K, Chiang J, Dingus BL, et al., EGRET upper limits to the high-energy gamma-ray emission from the millisecond pulsars in nearby globular clusters, Astrophys. J. 435, 218-224 (1994). crossref(new window)

Nakar E, Short-hard gamma-ray bursts, Phys. Rep. 442, 166-236 (2007). crossref(new window)

Nolan PL, Abdo AA, Ackermann M, Ajello M, Allafort A, et al., Fermi Large Area Telescope Second Source Catalog, Astrophys. J. Suppl. Ser. 199, 31-76 (2012). crossref(new window)

Ortolani S, Barbuy B, Bica E, Zoccali M, Renzini A, Distances of the bulge globular clusters Terzan 5, Liller 1, UKS 1, and Terzan 4 based on HST NICMOS photometry, Astron. Astrophys. 470, 1043-1049 (2007). 20066628 crossref(new window)

Pooley D, Lewin WHG, Anderson SF, Baumgardt H, Filippenko AV, et al., Dynamical Formation of Close Binary Systems in Globular Clusters, Astrophys. J. Lett. 591, L131 (2003). crossref(new window)

Stappers BW, Archibald AM, Hessels JWT, Bassa CG, Bogdanov S, et al., A State Change in the Missing Link Binary Pulsar System PSR J1023+0038, Astrophys. J. 790, 39-47 (2014). crossref(new window)

Strong AW, Moskalenko IV, Propagation of Cosmic-Ray Nucleons in the Galaxy, Astrophys. J. 509, 212-228 (1998). crossref(new window)

Takata J, Li KL, Leung GCK, Kong AKH, Tam PHT, et al., Multiwavelength Emissions from the Millisecond Pulsar Binary PSR J1023+0038 during an Accretion Active State, Astrophys J. 785, 131-137 (2014). crossref(new window)

Tam PHT, Kong AKH, Hui CY, Cheng KS, Li C, et al., Gammaray Emission from the Globular Clusters Liller 1, M80, NGC 6139, NGC 6541, NGC 6624, and NGC 6752, Astrophys. J. 729, 90-97 (2011). crossref(new window)

Tam PHT, Li KL, Kong AKH, Takata J, Leung GCK, et al., The birth of radio millisecond pulsars and their high-energy signature, in the 10th INTEGRAL Workshop, Annapolis, MD, 15-19 Sep 2014.

Venter C, de Jager OC, Constraining A General-Relativistic Frame-Dragging Model for Pulsed Radiation from a Population of Millisecond Pulsars in 47 Tucanae using GLAST LAT, Astrophys. J. Lett. 680, L125 (2008). crossref(new window)

Venter C, de Jager OC, Clapson AC, Predictions of Gamma-Ray Emission from Globular Cluster Millisecond Pulsars Above 100 MeV, Astrophys. J. Lett. 696, L52 (2009). crossref(new window)

Verbunt F, Hut P, The Globular Cluster Population of X-Ray Binaries, The Origin and Evolution of Neutron Stars, IAU Symposia 125, eds. Helfand DJ, Huang JH (Reidel Publishing Co., Dordrecht, 1987), 187-197.

Wu JHK, Hui CY, Wu EMH, Kong AKH, Huang RHH, et al., Search for Pulsed γ-Ray Emission from Globular Cluster M28, Astrophys. J. Lett. 765, L47 (2013). crossref(new window)