ALBERT

Description: A cornerstone of Einstein's special relativity is Lorentz invariance-the postulate that all observers measure exactly the same speed of light in vacuum, independent of photon-energy. While special relativity assumes that there is no fundamental length-scale associated with such invariance, there is a fundamental scale (the Planck scale, l(Planck) approximately 1.62 x 10(-33) cm or E(Planck) = M(Planck)c(2) approximately 1.22 x 10(19) GeV), at which quantum effects are expected to strongly affect the nature of space-time. There is great interest in the (not yet validated) idea that Lorentz invariance might break near the Planck scale. A key test of such violation of Lorentz invariance is a possible variation of photon speed with energy. Even a tiny variation in photon speed, when accumulated over cosmological light-travel times, may be revealed by observing sharp features in gamma-ray burst (GRB) light-curves. Here we report the detection of emission up to approximately 31 GeV from the distant and short GRB 090510. We find no evidence for the violation of Lorentz invariance, and place a lower limit of 1.2E(Planck) on the scale of a linear energy dependence (or an inverse wavelength dependence), subject to reasonable assumptions about the emission (equivalently we have an upper limit of l(Planck)/1.2 on the length scale of the effect). Our results disfavour quantum-gravity theories in which the quantum nature of space-time on a very small scale linearly alters the speed of light.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Abdo, A A -- Ackermann, M -- Ajello, M -- Asano, K -- Atwood, W B -- Axelsson, M -- Baldini, L -- Ballet, J -- Barbiellini, G -- Baring, M G -- Bastieri, D -- Bechtol, K -- Bellazzini, R -- Berenji, B -- Bhat, P N -- Bissaldi, E -- Bloom, E D -- Bonamente, E -- Bonnell, J -- Borgland, A W -- Bouvier, A -- Bregeon, J -- Brez, A -- Briggs, M S -- Brigida, M -- Bruel, P -- Burgess, J M -- Burnett, T H -- Caliandro, G A -- Cameron, R A -- Caraveo, P A -- Casandjian, J M -- Cecchi, C -- Celik, O -- Chaplin, V -- Charles, E -- Cheung, C C -- Chiang, J -- Ciprini, S -- Claus, R -- Cohen-Tanugi, J -- Cominsky, L R -- Connaughton, V -- Conrad, J -- Cutini, S -- Dermer, C D -- de Angelis, A -- de Palma, F -- Digel, S W -- Dingus, B L -- do Couto E Silva, E -- Drell, P S -- Dubois, R -- Dumora, D -- Farnier, C -- Favuzzi, C -- Fegan, S J -- Finke, J -- Fishman, G -- Focke, W B -- Foschini, L -- Fukazawa, Y -- Funk, S -- Fusco, P -- Gargano, F -- Gasparrini, D -- Gehrels, N -- Germani, S -- Gibby, L -- Giebels, B -- Giglietto, N -- Giordano, F -- Glanzman, T -- Godfrey, G -- Granot, J -- Greiner, J -- Grenier, I A -- Grondin, M-H -- Grove, J E -- Grupe, D -- Guillemot, L -- Guiriec, S -- Hanabata, Y -- Harding, A K -- Hayashida, M -- Hays, E -- Hoversten, E A -- Hughes, R E -- Johannesson, G -- Johnson, A S -- Johnson, R P -- Johnson, W N -- Kamae, T -- Katagiri, H -- Kataoka, J -- Kawai, N -- Kerr, M -- Kippen, R M -- Knodlseder, J -- Kocevski, D -- Kouveliotou, C -- Kuehn, F -- Kuss, M -- Lande, J -- Latronico, L -- Lemoine-Goumard, M -- Longo, F -- Loparco, F -- Lott, B -- Lovellette, M N -- Lubrano, P -- Madejski, G M -- Makeev, A -- Mazziotta, M N -- McBreen, S -- McEnery, J E -- McGlynn, S -- Meszaros, P -- Meurer, C -- Michelson, P F -- Mitthumsiri, W -- Mizuno, T -- Moiseev, A A -- Monte, C -- Monzani, M E -- Moretti, E -- Morselli, A -- Moskalenko, I V -- Murgia, S -- Nakamori, T -- Nolan, P L -- Norris, J P -- Nuss, E -- Ohno, M -- Ohsugi, T -- Omodei, N -- Orlando, E -- Ormes, J F -- Ozaki, M -- Paciesas, W S -- Paneque, D -- Panetta, J H -- Parent, D -- Pelassa, V -- Pepe, M -- Pesce-Rollins, M -- Petrosian, V -- Piron, F -- Porter, T A -- Preece, R -- Raino, S -- Ramirez-Ruiz, E -- Rando, R -- Razzano, M -- Razzaque, S -- Reimer, A -- Reimer, O -- Reposeur, T -- Ritz, S -- Rochester, L S -- Rodriguez, A Y -- Roth, M -- Ryde, F -- Sadrozinski, H F-W -- Sanchez, D -- Sander, A -- Saz Parkinson, P M -- Scargle, J D -- Schalk, T L -- Sgro, C -- Siskind, E J -- Smith, D A -- Smith, P D -- Spandre, G -- Spinelli, P -- Stamatikos, M -- Stecker, F W -- Strickman, M S -- Suson, D J -- Tajima, H -- Takahashi, H -- Takahashi, T -- Tanaka, T -- Thayer, J B -- Thayer, J G -- Thompson, D J -- Tibaldo, L -- Toma, K -- Torres, D F -- Tosti, G -- Troja, E -- Uchiyama, Y -- Uehara, T -- Usher, T L -- van der Horst, A J -- Vasileiou, V -- Vilchez, N -- Vitale, V -- von Kienlin, A -- Waite, A P -- Wang, P -- Wilson-Hodge, C -- Winer, B L -- Wood, K S -- Wu, X F -- Yamazaki, R -- Ylinen, T -- Ziegler, M -- England -- Nature. 2009 Nov 19;462(7271):331-4. doi: 10.1038/nature08574. Epub 2009 Oct 28.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Space Science Division, Naval Research Laboratory, Washington, District of Columbia 20375, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19865083" target="_blank"〉PubMed〈/a〉

Description: Pulsars are rapidly rotating, highly magnetized neutron stars emitting radiation across the electromagnetic spectrum. Although there are more than 1800 known radio pulsars, until recently only seven were observed to pulse in gamma rays, and these were all discovered at other wavelengths. The Fermi Large Area Telescope (LAT) makes it possible to pinpoint neutron stars through their gamma-ray pulsations. We report the detection of 16 gamma-ray pulsars in blind frequency searches using the LAT. Most of these pulsars are coincident with previously unidentified gamma-ray sources, and many are associated with supernova remnants. Direct detection of gamma-ray pulsars enables studies of emission mechanisms, population statistics, and the energetics of pulsar wind nebulae and supernova remnants.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Abdo, A A -- Ackermann, M -- Ajello, M -- Anderson, B -- Atwood, W B -- Axelsson, M -- Baldini, L -- Ballet, J -- Barbiellini, G -- Baring, M G -- Bastieri, D -- Baughman, B M -- Bechtol, K -- Bellazzini, R -- Berenji, B -- Bignami, G F -- Blandford, R D -- Bloom, E D -- Bonamente, E -- Borgland, A W -- Bregeon, J -- Brez, A -- Brigida, M -- Bruel, P -- Burnett, T H -- Caliandro, G A -- Cameron, R A -- Caraveo, P A -- Casandjian, J M -- Cecchi, C -- Celik, O -- Chekhtman, A -- Cheung, C C -- Chiang, J -- Ciprini, S -- Claus, R -- Cohen-Tanugi, J -- Conrad, J -- Cutini, S -- Dermer, C D -- de Angelis, A -- de Luca, A -- de Palma, F -- Digel, S W -- Dormody, M -- do Couto e Silva, E -- Drell, P S -- Dubois, R -- Dumora, D -- Farnier, C -- Favuzzi, C -- Fegan, S J -- Fukazawa, Y -- Funk, S -- Fusco, P -- Gargano, F -- Gasparrini, D -- Gehrels, N -- Germani, S -- Giebels, B -- Giglietto, N -- Giommi, P -- Giordano, F -- Glanzman, T -- Godfrey, G -- Grenier, I A -- Grondin, M-H -- Grove, J E -- Guillemot, L -- Guiriec, S -- Gwon, C -- Hanabata, Y -- Harding, A K -- Hayashida, M -- Hays, E -- Hughes, R E -- Johannesson, G -- Johnson, R P -- Johnson, T J -- Johnson, W N -- Kamae, T -- Katagiri, H -- Kataoka, J -- Kawai, N -- Kerr, M -- Knodlseder, J -- Kocian, M L -- Kuss, M -- Lande, J -- Latronico, L -- Lemoine-Goumard, M -- Longo, F -- Loparco, F -- Lott, B -- Lovellette, M N -- Lubrano, P -- Madejski, G M -- Makeev, A -- Marelli, M -- Mazziotta, M N -- McConville, W -- McEnery, J E -- Meurer, C -- Michelson, P F -- Mitthumsiri, W -- Mizuno, T -- Monte, C -- Monzani, M E -- Morselli, A -- Moskalenko, I V -- Murgia, S -- Nolan, P L -- Norris, J P -- Nuss, E -- Ohsugi, T -- Omodei, N -- Orlando, E -- Ormes, J F -- Paneque, D -- Parent, D -- Pelassa, V -- Pepe, M -- Pesce-Rollins, M -- Pierbattista, M -- Piron, F -- Porter, T A -- Primack, J R -- Raino, S -- Rando, R -- Ray, P S -- Razzano, M -- Rea, N -- Reimer, A -- Reimer, O -- Reposeur, T -- Ritz, S -- Rochester, L S -- Rodriguez, A Y -- Romani, R W -- Ryde, F -- Sadrozinski, H F-W -- Sanchez, D -- Sander, A -- Saz Parkinson, P M -- Scargle, J D -- Sgro, C -- Siskind, E J -- Smith, D A -- Smith, P D -- Spandre, G -- Spinelli, P -- Starck, J-L -- Strickman, M S -- Suson, D J -- Tajima, H -- Takahashi, H -- Takahashi, T -- Tanaka, T -- Thayer, J G -- Thompson, D J -- Tibaldo, L -- Tibolla, O -- Torres, D F -- Tosti, G -- Tramacere, A -- Uchiyama, Y -- Usher, T L -- Van Etten, A -- Vasileiou, V -- Vilchez, N -- Vitale, V -- Waite, A P -- Wang, P -- Watters, K -- Winer, B L -- Wolff, M T -- Wood, K S -- Ylinen, T -- Ziegler, M -- New York, N.Y. -- Science. 2009 Aug 14;325(5942):840-4. doi: 10.1126/science.1175558. Epub 2009 Jul 2.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Space Science Division, Naval Research Laboratory, Washington, DC 20375, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19574346" target="_blank"〉PubMed〈/a〉

Description: Pulsars are born with subsecond spin periods and slow by electromagnetic braking for several tens of millions of years, when detectable radiation ceases. A second life can occur for neutron stars in binary systems. They can acquire mass and angular momentum from their companions, to be spun up to millisecond periods and begin radiating again. We searched Fermi Large Area Telescope data for pulsations from all known millisecond pulsars (MSPs) outside of globular clusters, using rotation parameters from radio telescopes. Strong gamma-ray pulsations were detected for eight MSPs. The gamma-ray pulse profiles and spectral properties resemble those of young gamma-ray pulsars. The basic emission mechanism seems to be the same for MSPs and young pulsars, with the emission originating in regions far from the neutron star surface.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Abdo, A A -- Ackermann, M -- Ajello, M -- Atwood, W B -- Axelsson, M -- Baldini, L -- Ballet, J -- Barbiellini, G -- Baring, M G -- Bastieri, D -- Baughman, B M -- Bechtol, K -- Bellazzini, R -- Berenji, B -- Bignami, G F -- Blandford, R D -- Bloom, E D -- Bonamente, E -- Borgland, A W -- Bregeon, J -- Brez, A -- Brigida, M -- Bruel, P -- Burnett, T H -- Caliandro, G A -- Cameron, R A -- Camilo, F -- Caraveo, P A -- Carlson, P -- Casandjian, J M -- Cecchi, C -- Celik, O -- Charles, E -- Chekhtman, A -- Cheung, C C -- Chiang, J -- Ciprini, S -- Claus, R -- Cognard, I -- Cohen-Tanugi, J -- Cominsky, L R -- Conrad, J -- Corbet, R -- Cutini, S -- Dermer, C D -- Desvignes, G -- de Angelis, A -- de Luca, A -- de Palma, F -- Digel, S W -- Dormody, M -- do Couto e Silva, E -- Drell, P S -- Dubois, R -- Dumora, D -- Edmonds, Y -- Farnier, C -- Favuzzi, C -- Fegan, S J -- Focke, W B -- Frailis, M -- Freire, P C C -- Fukazawa, Y -- Funk, S -- Fusco, P -- Gargano, F -- Gasparrini, D -- Gehrels, N -- Germani, S -- Giebels, B -- Giglietto, N -- Giordano, F -- Glanzman, T -- Godfrey, G -- Grenier, I A -- Grondin, M H -- Grove, J E -- Guillemot, L -- Guiriec, S -- Hanabata, Y -- Harding, A K -- Hayashida, M -- Hays, E -- Hobbs, G -- Hughes, R E -- Johannesson, G -- Johnson, A S -- Johnson, R P -- Johnson, T J -- Johnson, W N -- Johnston, S -- Kamae, T -- Katagiri, H -- Kataoka, J -- Kawai, N -- Kerr, M -- Knodlseder, J -- Kocian, M L -- Kramer, M -- Kuss, M -- Lande, J -- Latronico, L -- Lemoine-Goumard, M -- Longo, F -- Loparco, F -- Lott, B -- Lovellette, M N -- Lubrano, P -- Madejski, G M -- Makeev, A -- Manchester, R N -- Marelli, M -- Mazziotta, M N -- McConville, W -- McEnery, J E -- McLaughlin, M A -- Meurer, C -- Michelson, P F -- Mitthumsiri, W -- Mizuno, T -- Moiseev, A A -- Monte, C -- Monzani, M E -- Morselli, A -- Moskalenko, I V -- Murgia, S -- Nolan, P L -- Norris, J P -- Nuss, E -- Ohsugi, T -- Omodei, N -- Orlando, E -- Ormes, J F -- Paneque, D -- Panetta, J H -- Parent, D -- Pelassa, V -- Pepe, M -- Pesce-Rollins, M -- Piron, F -- Porter, T A -- Raino, S -- Rando, R -- Ransom, S M -- Ray, P S -- Razzano, M -- Rea, N -- Reimer, A -- Reimer, O -- Reposeur, T -- Ritz, S -- Rochester, L S -- Rodriguez, A Y -- Romani, R W -- Roth, M -- Ryde, F -- Sadrozinski, H F W -- Sanchez, D -- Sander, A -- Saz Parkinson, P M -- Scargle, J D -- Schalk, T L -- Sgro, C -- Siskind, E J -- Smith, D A -- Smith, P D -- Spandre, G -- Spinelli, P -- Stappers, B W -- Starck, J L -- Striani, E -- Strickman, M S -- Suson, D J -- Tajima, H -- Takahashi, H -- Tanaka, T -- Thayer, J B -- Thayer, J G -- Theureau, G -- Thompson, D J -- Thorsett, S E -- Tibaldo, L -- Torres, D F -- Tosti, G -- Tramacere, A -- Uchiyama, Y -- Usher, T L -- Van Etten, A -- Vasileiou, V -- Venter, C -- Vilchez, N -- Vitale, V -- Waite, A P -- Wallace, E -- Wang, P -- Watters, K -- Webb, N -- Weltevrede, P -- Winer, B L -- Wood, K S -- Ylinen, T -- Ziegler, M -- New York, N.Y. -- Science. 2009 Aug 14;325(5942):848-52. doi: 10.1126/science.1176113.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Space Science Division, Naval Research Laboratory,Washington, DC 20375, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19574349" target="_blank"〉PubMed〈/a〉

Description: We report the detection of gamma-ray emissions above 200 megaelectron volts at a significance level of 17sigma from the globular cluster 47 Tucanae, using data obtained with the Large Area Telescope onboard the Fermi Gamma-ray Space Telescope. Globular clusters are expected to emit gamma rays because of the large populations of millisecond pulsars that they contain. The spectral shape of 47 Tucanae is consistent with gamma-ray emission from a population of millisecond pulsars. The observed gamma-ray luminosity implies an upper limit of 60 millisecond pulsars present in 47 Tucanae.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Abdo, A A -- Ackermann, M -- Ajello, M -- Atwood, W B -- Axelsson, M -- Baldini, L -- Ballet, J -- Barbiellini, G -- Bastieri, D -- Baughman, B M -- Bechtol, K -- Bellazzini, R -- Berenji, B -- Blandford, R D -- Bloom, E D -- Bonamente, E -- Borgland, A W -- Bregeon, J -- Brez, A -- Brigida, M -- Bruel, P -- Burnett, T H -- Caliandro, G A -- Cameron, R A -- Caraveo, P A -- Casandjian, J M -- Cecchi, C -- Celik, O -- Charles, E -- Chaty, S -- Chekhtman, A -- Cheung, C C -- Chiang, J -- Ciprini, S -- Claus, R -- Cohen-Tanugi, J -- Conrad, J -- Cutini, S -- Dermer, C D -- de Palma, F -- Digel, S W -- Dormody, M -- do Couto e Silva, E -- Drell, P S -- Dubois, R -- Dumora, D -- Farnier, C -- Favuzzi, C -- Fegan, S J -- Focke, W B -- Frailis, M -- Fukazawa, Y -- Fusco, P -- Gargano, F -- Gasparrini, D -- Gehrels, N -- Germani, S -- Giebels, B -- Giglietto, N -- Giordano, F -- Glanzman, T -- Godfrey, G -- Grenier, I A -- Grove, J E -- Guillemot, L -- Guiriec, S -- Hanabata, Y -- Harding, A K -- Hayashida, M -- Hays, E -- Horan, D -- Hughes, R E -- Johannesson, G -- Johnson, A S -- Johnson, R P -- Johnson, T J -- Johnson, W N -- Kamae, T -- Katagiri, H -- Kawai, N -- Kerr, M -- Knodlseder, J -- Kuehn, F -- Kuss, M -- Lande, J -- Latronico, L -- Lemoine-Goumard, M -- Longo, F -- Loparco, F -- Lott, B -- Lovellette, M N -- Lubrano, P -- Makeev, A -- Mazziotta, M N -- McConville, W -- McEnery, J E -- Meurer, C -- Michelson, P F -- Mitthumsiri, W -- Mizuno, T -- Moiseev, A A -- Monte, C -- Monzani, M E -- Morselli, A -- Moskalenko, I V -- Murgia, S -- Nolan, P L -- Norris, J P -- Nuss, E -- Ohsugi, T -- Omodei, N -- Orlando, E -- Ormes, J F -- Paneque, D -- Panetta, J H -- Parent, D -- Pelassa, V -- Pepe, M -- Pierbattista, M -- Piron, F -- Porter, T A -- Raino, S -- Rando, R -- Razzano, M -- Rea, N -- Reimer, A -- Reimer, O -- Reposeur, T -- Ritz, S -- Rochester, L S -- Rodriguez, A Y -- Romani, R W -- Roth, M -- Ryde, F -- Sadrozinski, H F-W -- Sanchez, D -- Sander, A -- Saz Parkinson, P M -- Sgro, C -- Smith, D A -- Smith, P D -- Spandre, G -- Spinelli, P -- Starck, J-L -- Strickman, M S -- Suson, D J -- Tajima, H -- Takahashi, H -- Tanaka, T -- Thayer, J B -- Thayer, J G -- Thompson, D J -- Tibaldo, L -- Torres, D F -- Tosti, G -- Tramacere, A -- Uchiyama, Y -- Usher, T L -- Vasileiou, V -- Vilchez, N -- Vitale, V -- Wang, P -- Webb, N -- Winer, B L -- Wood, K S -- Ylinen, T -- Ziegler, M -- New York, N.Y. -- Science. 2009 Aug 14;325(5942):845-8. doi: 10.1126/science.1177023.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Space Science Division, Naval Research Laboratory, Washington, DC 20375, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19679807" target="_blank"〉PubMed〈/a〉