Pulsars, transients and relativistic astrophysics

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Phase-resolved Faraday rotation in pulsars

ArXiv 0903.5511 (2009)

Authors:

A Noutsos, A Karastergiou, M Kramer, S Johnston, BW Stappers

Abstract:

We have detected significant Rotation Measure variations for 9 bright pulsars, as a function of pulse longitude. An additional sample of 10 pulsars showed a rather constant RM with phase, yet a small degree of RM fluctuation is visible in at least 3 of those cases. In all cases, we have found that the rotation of the polarization position angle across our 1.4 GHz observing band is consistent with the wavelength-squared law of interstellar Faraday Rotation. We provide for the first time convincing evidence that RM variations across the pulse are largely due to interstellar scattering, although we cannot exclude that magnetospheric Faraday Rotation may still have a minor contribution; alternative explanations of this phenomenon, like erroneous de-dispersion and the presence of non-orthogonal polarization modes, are excluded. If the observed, phase-resolved RM variations are common amongst pulsars, then many of the previously measured pulsar RMs may be in error by as much as a few tens of rad m-2.
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All-sky LIGO search for periodic gravitational waves in the early fifth-science-run data.

Phys Rev Lett 102:11 (2009) 111102

Authors:

BP Abbott, R Abbott, R Adhikari, P Ajith, B Allen, G Allen, RS Amin, SB Anderson, WG Anderson, MA Arain, M Araya, H Armandula, P Armor, Y Aso, S Aston, P Aufmuth, C Aulbert, S Babak, P Baker, S Ballmer, H Bantilan, BC Barish, C Barker, D Barker, B Barr, P Barriga, L Barsotti, MA Barton, I Bartos, R Bassiri, M Bastarrika, B Behnke, M Benacquista, J Betzwieser, PT Beyersdorf, IA Bilenko, G Billingsley, R Biswas, E Black, JK Blackburn, L Blackburn, D Blair, B Bland, TP Bodiya, L Bogue, R Bork, V Boschi, S Bose, PR Brady, VB Braginsky, JE Brau, M Brinkmann, AF Brooks, DA Brown, G Brunet, A Bullington, A Buonanno, O Burmeister, RL Byer, L Cadonati, G Cagnoli, JB Camp, J Cannizzo, KC Cannon, J Cao, L Cardenas, V Cardoso, S Caride, T Casebolt, G Castaldi, S Caudill, M Cavaglià, C Cepeda, E Chalkley, P Charlton, S Chatterji, S Chelkowski, Y Chen, N Christensen, D Clark, J Clark, JH Clayton, T Cokelaer, R Conte, D Cook, TRC Corbitt, N Cornish, DC Coyne, JDE Creighton, TD Creighton, AM Cruise, A Cumming, L Cunningham, RM Cutler, K Danzmann, B Daudert, G Davies, D Debra, J Degallaix, V Dergachev, S Desai, R Desalvo, S Dhurandhar, M Díaz, J Dickson, A Dietz, F Donovan, KL Dooley, EE Doomes, RWP Drever, I Duke, J-C Dumas, J Dwyer, C Echols, M Edgar, A Effler, P Ehrens, G Ely, E Espinoza, T Etzel, M Evans, T Evans, S Fairhurst, Y Faltas, Y Fan, D Fazi, MM Fejer, LS Finn, K Flasch, S Foley, C Forrest, N Fotopoulos, A Franzen, Z Frei, A Freise, R Frey, TT Fricke, P Fritschel, VV Frolov, M Fyffe, JA Garofoli, I Gholami, JA Giaime, S Giampanis, KD Giardina, K Goda, E Goetz, LM Goggin, G González, S Gossler, R Gouaty, A Grant, S Gras, C Gray, M Gray, RJS Greenhalgh, AM Gretarsson, F Grimaldi, R Grosso, H Grote, S Grunewald, M Guenther, EK Gustafson, R Gustafson, B Hage, JM Hallam, C Hanna, J Hanson, J Harms, GM Harry, ED Harstad, E Haughian, K Hayama, T Hayler, J Heefner, IS Heng, A Heptonstall, M Hewitson, S Hild, E Hirose, D Hoak, K Holt, D Hosken, J Hough, SH Huttner, D Ingram, M Ito, A Ivanov, B Johnson, WW Johnson, DI Jones, G Jones, R Jones, L Ju, P Kalmus, V Kalogera, S Kamat, J Kanner, D Kasprzyk, E Katsavounidis, K Kawabe, S Kawamura, F Kawazoe, W Kells, DG Keppel, A Khalaidovski, F Ya Khalili, R Khan, E Khazanov, P King, JS Kissel, S Klimenko, B Kocsis, K Kokeyama, V Kondrashov, R Kopparapu, S Koranda, D Kozak, I Kozhevatov, B Krishnan, P Kwee, M Landry, B Lantz, A Lazzarini, M Lei, I Leonor, C Li, H Lin, PE Lindquist, TB Littenberg, NA Lockerbie, D Lodhia, M Lormand, P Lu, M Lubinski, A Lucianetti, H Lück, B Machenschalk, M Macinnis, M Mageswaran, K Mailand, I Mandel, V Mandic, S Márka, Z Márka, A Markosyan, J Markowitz, E Maros, IW Martin, RM Martin, JN Marx, K Mason, F Matichard, L Matone, R Matzner, N Mavalvala, R McCarthy, DE McClelland, SC McGuire, M McHugh, G McIntyre, D McKechan, K McKenzie, M Mehmet, A Melissinos, G Mendell, RA Mercer, S Meshkov, CJ Messenger, D Meyers, A Miller, J Miller, J Minelli, S Mitra, VP Mitrofanov, G Mitselmakher, R Mittleman, O Miyakawa, B Moe, SD Mohanty, G Moreno, K Mors, K Mossavi, C Mowlowry, G Mueller, D Muhammad, S Mukherjee, H Mukhopadhyay, A Mullavey, H Müller-Ebhardt, J Munch, PG Murray, E Myers, J Myers, T Nash, J Nelson, G Newton, A Nishizawa, K Numata, E Ochsner, J O'Dell, G Ogin, B O'Reilly, R O'Shaughnessy, DJ Ottaway, RS Ottens, H Overmier, BJ Owen, Y Pan, C Pankow, MA Papa, V Parameshwaraiah, P Patel, M Pedraza, S Penn, A Perraca, T Petrie, IM Pinto, M Pitkin, HJ Pletsch, MV Plissi, F Postiglione, M Principe, R Prix, V Quetschke, FJ Raab, DS Rabeling, H Radkins, P Raffai, N Rainer, M Rakhmanov, M Ramsunder, T Reed, H Rehbein, S Reid, DH Reitze, R Riesen, K Riles, B Rivera, NA Robertson, C Robinson, EL Robinson, S Roddy, AM Rogan, J Rollins, JD Romano, JH Romie, S Rowan, A Rüdiger, L Ruet, P Russell, K Ryan, S Sakata, L Sancho de la Jordana, V Sandberg, V Sannibale, L Santamaria, S Saraf, P Sarin, BS Sathyaprakash, S Sato, PR Saulson, R Savage, P Savov, M Scanlan, SW Schediwy, R Schilling, R Schnabel, R Schofield, BF Schutz, P Schwinberg, J Scott, SM Scott, AC Searle, B Sears, F Seifert, D Sellers, AS Sengupta, A Sergeev, B Shapiro, P Shawhan, DH Shoemaker, A Sibley, X Siemens, D Sigg, S Sinha, AM Sintes, BJJ Slagmolen, J Slutsky, JR Smith, MR Smith, ND Smith, K Somiya, B Sorazu, LC Stein, KA Strain, A Stuver, TZ Summerscales, K-X Sun, M Sung, PJ Sutton, H Takahashi, DB Tanner, R Taylor, R Taylor, J Thacker, KA Thorne, KS Thorne, A Thüring, KV Tokmakov, C Torres, C Torrie, G Traylor, M Trias, D Ugolini, K Urbanek, H Vahlbruch, C Van Den Broeck, MV van der Sluys, AA van Veggel, S Vass, R Vaulin, A Vecchio, JD Veitch, P Veitch, A Villar, C Vorvick, SP Vyachanin, SJ Waldman, L Wallace, H Ward, RL Ward, M Weinert, AJ Weinstein, R Weiss, L Wen, S Wen, K Wette, JT Whelan, SE Whitcomb, BF Whiting, C Wilkinson, PA Willems, HR Williams, L Williams, B Willke, I Wilmut, W Winkler, CC Wipf, AG Wiseman, G Woan, R Wooley, J Worden, W Wu, I Yakushin, H Yamamoto, Z Yan, S Yoshida, M Zanolin, J Zhang, L Zhang, C Zhao, N Zotov, ME Zucker, H Zur Mühlen, J Zweizig, LIGO Scientific Collaboration

Abstract:

We report on an all-sky search with the LIGO detectors for periodic gravitational waves in the frequency range 50-1100 Hz and with the frequency's time derivative in the range -5 x 10{-9}-0 Hz s{-1}. Data from the first eight months of the fifth LIGO science run (S5) have been used in this search, which is based on a semicoherent method (PowerFlux) of summing strain power. Observing no evidence of periodic gravitational radiation, we report 95% confidence-level upper limits on radiation emitted by any unknown isolated rotating neutron stars within the search range. Strain limits below 10{-24} are obtained over a 200-Hz band, and the sensitivity improvement over previous searches increases the spatial volume sampled by an average factor of about 100 over the entire search band. For a neutron star with nominal equatorial ellipticity of 10{-6}, the search is sensitive to distances as great as 500 pc.
More details from the publisher

All-sky LIGO search for periodic gravitational waves in the early fifth-science-run data.

Physical review letters 102:11 (2009) 111102

Authors:

BP Abbott, R Abbott, R Adhikari, P Ajith, B Allen, G Allen, RS Amin, SB Anderson, WG Anderson, MA Arain, M Araya, H Armandula, P Armor, Y Aso, S Aston, P Aufmuth, C Aulbert, S Babak, P Baker, S Ballmer, H Bantilan, BC Barish, C Barker, D Barker, B Barr, P Barriga, L Barsotti, MA Barton, I Bartos, R Bassiri, M Bastarrika, B Behnke, M Benacquista, J Betzwieser, PT Beyersdorf, IA Bilenko, G Billingsley, R Biswas, E Black, JK Blackburn, L Blackburn, D Blair, B Bland, TP Bodiya, L Bogue, R Bork, V Boschi, S Bose, PR Brady, VB Braginsky, JE Brau, M Brinkmann, AF Brooks, DA Brown, G Brunet, A Bullington, A Buonanno, O Burmeister, RL Byer, L Cadonati, G Cagnoli, JB Camp, J Cannizzo, KC Cannon, J Cao, L Cardenas, V Cardoso, S Caride, T Casebolt, G Castaldi, S Caudill, M Cavaglià, C Cepeda, E Chalkley, P Charlton, S Chatterji, S Chelkowski, Y Chen, N Christensen, D Clark, J Clark, JH Clayton, T Cokelaer, R Conte, D Cook, TRC Corbitt, N Cornish, DC Coyne, JDE Creighton, TD Creighton, AM Cruise, A Cumming, L Cunningham, RM Cutler, K Danzmann, B Daudert, G Davies, D Debra, J Degallaix, V Dergachev, S Desai, R Desalvo, S Dhurandhar, M Díaz, J Dickson, A Dietz, F Donovan, KL Dooley, EE Doomes, RWP Drever, I Duke, J-C Dumas, J Dwyer, C Echols, M Edgar, A Effler, P Ehrens, G Ely, E Espinoza, T Etzel, M Evans, T Evans, S Fairhurst, Y Faltas, Y Fan, D Fazi, MM Fejer, LS Finn, K Flasch, S Foley, C Forrest, N Fotopoulos, A Franzen, Z Frei, A Freise, R Frey, TT Fricke, P Fritschel, VV Frolov, M Fyffe, JA Garofoli, I Gholami, JA Giaime, S Giampanis, KD Giardina, K Goda, E Goetz, LM Goggin, G González, S Gossler, R Gouaty, A Grant, S Gras, C Gray, M Gray, RJS Greenhalgh, AM Gretarsson, F Grimaldi, R Grosso, H Grote, S Grunewald, M Guenther, EK Gustafson, R Gustafson, B Hage, JM Hallam, C Hanna, J Hanson, J Harms, GM Harry, ED Harstad, E Haughian, K Hayama, T Hayler, J Heefner, IS Heng, A Heptonstall, M Hewitson, S Hild, E Hirose, D Hoak, K Holt, D Hosken, J Hough, SH Huttner, D Ingram, M Ito, A Ivanov, B Johnson, WW Johnson, DI Jones, G Jones, R Jones, L Ju, P Kalmus, V Kalogera, S Kamat, J Kanner, D Kasprzyk, E Katsavounidis, K Kawabe, S Kawamura, F Kawazoe, W Kells, DG Keppel, A Khalaidovski, F Ya Khalili, R Khan, E Khazanov, P King, JS Kissel, S Klimenko, B Kocsis, K Kokeyama, V Kondrashov, R Kopparapu, S Koranda, D Kozak, I Kozhevatov, B Krishnan, P Kwee, M Landry, B Lantz, A Lazzarini, M Lei, I Leonor, C Li, H Lin, PE Lindquist, TB Littenberg, NA Lockerbie, D Lodhia, M Lormand, P Lu, M Lubinski, A Lucianetti, H Lück, B Machenschalk, M Macinnis, M Mageswaran, K Mailand, I Mandel, V Mandic, S Márka, Z Márka, A Markosyan, J Markowitz, E Maros, IW Martin, RM Martin, JN Marx, K Mason, F Matichard, L Matone, R Matzner, N Mavalvala, R McCarthy, DE McClelland, SC McGuire, M McHugh, G McIntyre, D McKechan, K McKenzie, M Mehmet, A Melissinos, G Mendell, RA Mercer, S Meshkov, CJ Messenger, D Meyers, A Miller, J Miller, J Minelli, S Mitra, VP Mitrofanov, G Mitselmakher, R Mittleman, O Miyakawa, B Moe, SD Mohanty, G Moreno, K Mors, K Mossavi, C Mowlowry, G Mueller, D Muhammad, S Mukherjee, H Mukhopadhyay, A Mullavey, H Müller-Ebhardt, J Munch, PG Murray, E Myers, J Myers, T Nash, J Nelson, G Newton, A Nishizawa, K Numata, E Ochsner, J O'Dell, G Ogin, B O'Reilly, R O'Shaughnessy, DJ Ottaway, RS Ottens, H Overmier, BJ Owen, Y Pan, C Pankow, MA Papa, V Parameshwaraiah, P Patel, M Pedraza, S Penn, A Perraca, T Petrie, IM Pinto, M Pitkin, HJ Pletsch, MV Plissi, F Postiglione, M Principe, R Prix, V Quetschke, FJ Raab, DS Rabeling, H Radkins, P Raffai, N Rainer, M Rakhmanov, M Ramsunder, T Reed, H Rehbein, S Reid, DH Reitze, R Riesen, K Riles, B Rivera, NA Robertson, C Robinson, EL Robinson, S Roddy, AM Rogan, J Rollins, JD Romano, JH Romie, S Rowan, A Rüdiger, L Ruet, P Russell, K Ryan, S Sakata, L Sancho de la Jordana, V Sandberg, V Sannibale, L Santamaria, S Saraf, P Sarin, BS Sathyaprakash, S Sato, PR Saulson, R Savage, P Savov, M Scanlan, SW Schediwy, R Schilling, R Schnabel, R Schofield, BF Schutz, P Schwinberg, J Scott, SM Scott, AC Searle, B Sears, F Seifert, D Sellers, AS Sengupta, A Sergeev, B Shapiro, P Shawhan, DH Shoemaker, A Sibley, X Siemens, D Sigg, S Sinha, AM Sintes, BJJ Slagmolen, J Slutsky, JR Smith, MR Smith, ND Smith, K Somiya, B Sorazu, LC Stein, KA Strain, A Stuver, TZ Summerscales, K-X Sun, M Sung, PJ Sutton, H Takahashi, DB Tanner, R Taylor, R Taylor, J Thacker, KA Thorne, KS Thorne, A Thüring, KV Tokmakov, C Torres, C Torrie, G Traylor, M Trias, D Ugolini, K Urbanek, H Vahlbruch, C Van Den Broeck, MV van der Sluys, AA van Veggel, S Vass, R Vaulin, A Vecchio, JD Veitch, P Veitch, A Villar, C Vorvick, SP Vyachanin, SJ Waldman, L Wallace, H Ward, RL Ward, M Weinert, AJ Weinstein, R Weiss, L Wen, S Wen, K Wette, JT Whelan, SE Whitcomb, BF Whiting, C Wilkinson, PA Willems, HR Williams, L Williams, B Willke, I Wilmut, W Winkler, CC Wipf, AG Wiseman, G Woan, R Wooley, J Worden, W Wu, I Yakushin, H Yamamoto, Z Yan, S Yoshida, M Zanolin, J Zhang, L Zhang, C Zhao, N Zotov, ME Zucker, H Zur Mühlen, J Zweizig, LIGO Scientific Collaboration

Abstract:

We report on an all-sky search with the LIGO detectors for periodic gravitational waves in the frequency range 50-1100 Hz and with the frequency's time derivative in the range -5 x 10{-9}-0 Hz s{-1}. Data from the first eight months of the fifth LIGO science run (S5) have been used in this search, which is based on a semicoherent method (PowerFlux) of summing strain power. Observing no evidence of periodic gravitational radiation, we report 95% confidence-level upper limits on radiation emitted by any unknown isolated rotating neutron stars within the search range. Strain limits below 10{-24} are obtained over a 200-Hz band, and the sensitivity improvement over previous searches increases the spatial volume sampled by an average factor of about 100 over the entire search band. For a neutron star with nominal equatorial ellipticity of 10{-6}, the search is sensitive to distances as great as 500 pc.
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Searching for substellar companions of young isolated neutron stars*

Astronomy & Astrophysics EDP Sciences 496:2 (2009) 533-545

Authors:

B Posselt, R Neuhäuser, F Haberl
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The extended X-ray emission around HDF130 at z=1.99: an inverse Compton ghost of a giant radio source in the Chandra Deep Field North

ArXiv 0902.3117 (2009)

Authors:

AC Fabian, S Chapman, CM Casey, F Bauer, KM Blundell

Abstract:

One of the six extended X-ray sources found in the Chandra DeepField North is centred on HDF130, which has recently been shown to be a massive galaxy at z=1.99 with a compact radio nucleus. The X-ray source has a roughly double-lobed structure with each lobe about 41 arcsec long, or 345 kpc at the redshift of HDF130. We have analyzed the 2 Ms X-ray image and spectrum of the source and find that it is well fit by a power-law continuum of photon index 2.65 and has a 2--10 keV luminosity of 5.4x10^{43}ergps (if at z=1.99). Any further extended emission within a radius of 60 arcsec has a luminosity less than half this value, which is contrary to what is expected from a cluster of galaxies. The source is best explained as an inverse Compton ghost of a giant radio source, which is no longer being powered, and for which Compton losses have downgraded the energetic electrons, \gamma> 10^4, required for high-frequency radio emission. The lower energy electrons, \gamma~1000, produce X-rays by inverse Compton scattering on the Cosmic Microwave Background. Depending on the magnetic field strength, some low frequency radio emission may remain. Further inverse Compton ghosts may exist in the Chandra deep fields.
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