Results 21 to 30 of about 371,246 (330)

Supernovae and Positron Annihilation [PDF]

, 2001
Radioactive nuclei, especially those created in SN explosion, have long been suggested to be important contributors of galactic positrons. In this paper we describe the findings of three independent OSSE/SMM/TGRS studies of positron annihilation ...
Chan, Cheng, Dermer, Harris, Hatano, Howell, J.D Kurfess, Johnson, Jose, Kinzer, Kinzer, Leising, M.D Leising, Milne, Milne, Ore, P.A Milne, Purcell, R.L Kinzer, Share, Timmes, Woosley   +21 more
core   +3 more sources

Low-frequency Faraday rotation measures towards pulsars using LOFAR: probing the 3D Galactic halo magnetic field [PDF]

Monthly notices of the Royal Astronomical Society, 2019
We determined Faraday rotation measures (RMs) towards 137 pulsars in the northern sky, using Low-Frequency Array (LOFAR) observations at 110–190 MHz. This low-frequency RM catalogue, the largest to date, improves the precision of existing RM measurements
C. Sobey, A. Bilous, J. Grießmeier, J. Hessels, A. Karastergiou, E. Keane, V. Kondratiev, M. Kramer, D. Michilli, A. Noutsos, M. Pilia, E. J. Polzin, B. Stappers, C. M. Tan, J. V. Leeuwen, J. Verbiest, P. Weltevrede, G. Heald, M. I. R. Alves, E. Carretti, T. Enßlin, M. Haverkorn, M. Iacobelli, W. Reich, C. University, C. Astronomy, S. Science, Astron Netherlands Institute for Radio Astronomy Anton Pa Astronomy, L. -. U. D. Cnrs, Station de radioastronomie de Nanccay, O. Astrophysics, Department of Physics Astronomy University of the Western Cape, Department of Applied Physics, Electronics Rhodes University, Ska Organisation, A. Institute, M. F. Astronomy, Department of Physics - California Lutheran University, M. S. Institute, I. Cagliari, J. B. C. F. Astrophysics, Fakultat fur Physik Universitat Bielefeld, D. O. U. O. Nijmegen, I. D. Radioastronomia, M. F. Astrophysik, D. I. F. Astronomy, Astrophysics   +46 more
semanticscholar   +1 more source

Galactic Dynamos [PDF]

Annual Review of Astronomy and Astrophysics, 2022
Spiral galaxies, including the Milky Way, have large-scale magnetic fields with significant energy densities. The dominant theory attributes these magnetic fields to a large-scale dynamo.
A. Brandenburg, E. Ntormousi
semanticscholar   +1 more source

Using Cepheids to determine the galactic abundance gradient I. The solar neighbourhood [PDF]

, 2001
A number of studies of abundance gradients in the galactic disk have been performed in recent years. The results obtained are rather disparate: from no detectable gradient to a rather significant slope of about -0.1 dex kpc -1. The present study concerns
Afflerbach, Amaral, Andrievsky, Andrievsky, Andrievsky, Andrievsky, B. Barbuy, Barklem, Blitz, Cameron, Carraro, Cunha, D. Bersier, Daflon, Deharveng, Dennisenkov, Dennisenkov, Dennisenkov, Edmunds, Evans, Fernie, Fernley, Fich, Fitzsimmons, Fitzsimmons, Friel, Friel, Friel, Fry, Fux, Fux, Geisler, Gieren, Gies, Gough, Grevesse, Gummersbach, Harris, Harris, Harris, Hill, Hou, J. R. D. Lépine, Janes, Kaufer, Kilian, Kilian, Kilian-Montenbruck, Kiss, Kovtyukh, Kovtyukh, Lacey, Laney, Luck, Luck, Luck, Lépine, Lépine, López-Corredoira, Maciel, Maciel, Martin, Martinet, McNamara, Neese, Panagia, Pasquali, Petersen, Peña, Portinari, R. E. Luck, R. U. Karpischek, Raboud, Rastorguev, Rodriguez, Rolleston, Rudolph, S. M. Andrievsky, Sasselov, Schaller, Shaver, Simpson, Simpson, Smartt, Stark, Thogersen, Travaglio, Turner, V. E. Panchuk, V. G. Klochkova, V. V. Kovtyukh, Vilchez, W. J. Maciel   +92 more
core   +2 more sources

Circumstellar disc lifetimes in numerous galactic young stellar clusters [PDF]

, 2018
We thank the referee for his/her very helpful comments. We thank K. Luhman, E. Mamajek, M. Pecaut, G. Somers, and R. Jeffries for stimulating discussions. The MYStIX project is now supported by the Chandra archive grant AR7-18002X.
Alexander J. W. Richert, K. Getman, E. Feigelson, M. Kuhn, P. Broos, M. Povich, M. Bate, G. P. G. P. S. University, Univ. de Valparaiso, M. I. O. Astrophysics, California Polytechnic State University, U. Exeter, Huntingdon Institute for X-ray Astronomy   +12 more
semanticscholar   +1 more source

Detection of the gravitational redshift in the orbit of the star S2 near the Galactic centre massive black hole [PDF]

Astronomy & Astrophysics, 2018
The highly elliptical, 16-year-period orbit of the star S2 around the massive black hole candidate Sgr A✻ is a sensitive probe of the gravitational field in the Galactic centre.
G. C. R. Abuter, A. Amorim, N. Anugu, M. Baubock, M. Benisty, J. Berger, N. Blind, H. Bonnet, W. Brandner, A. Buron, C. Collin, F. Chapron, Y. Cl'enet, V. C. D. Foresto, P. Zeeuw, C. Deen, F. Delplancke-Strobele, R. Dembet, J. Dexter, G. Duvert, A. Eckart, F. Eisenhauer, G. Finger, N. F. Schreiber, P. F'edou, P. Garcia, R. G. López, F. Gao, E. Gendron, R. Genzel, S. Gillessen, P. Gordo, M. Habibi, X. Haubois, M. Haug, F. Haussmann, T. Henning, S. Hippler, M. Horrobin, Z. Hubert, N. Hubin, A. Rosales, L. Jochum, L. Jocou, A. Kaufer, S. Kellner, S. Kendrew, P. Kervella, Y. Kok, M. Kulas, S. Lacour, V. Lapeyrère, B. Lazareff, J. L. Bouquin, P. L'ena, M. Lippa, R. Lenzen, A. M'erand, E. Muller, U. Neumann, T. Ott, L. Palanca, T. Paumard, L. Pasquini, K. Perraut, G. Perrin, O. Pfuhl, P. Plewa, S. Rabien, A. Ram'irez, J. Ramos, C. Rau, G. Rodr'iguez-Coira, R. Rohloff, G. Rousset, J. Sánchez-Bermúdez, S. Scheithauer, M. Scholler, N. Schuler, J. Spyromilio, O. Straub, C. Straubmeier, E. Sturm, L. Tacconi, K. Tristram, F. Vincent, S. Fellenberg, I. Wank, I. Waisberg, F. Widmann, E. Wieprecht, M. Wiest, E. Wiezorrek, J. Woillez, Ş. Yazici, D. Ziegler, G. Zins   +96 more
semanticscholar   +1 more source

Hunting for open clusters in Gaia DR2: 582 new open clusters in the Galactic disc [PDF]

Astronomy & Astrophysics, 2020
Context. Open clusters are key targets for studies of Galaxy structure and evolution, and stellar physics. Since the Gaia data release 2 (DR2), the discovery of undetected clusters has shown that previous surveys were incomplete. Aims.
A. Castro-Ginard, C. Jordi, X. Luri, J. Álvarez Cid-Fuentes, L. Casamiquela, F. Anders, T. Cantat-Gaudin, M. Mongui'o, L. Balaguer-Núñez, S. Solà, Rosa M. Badia   +10 more
semanticscholar   +1 more source

The long bar as seen by the VVV Survey: II. Star counts [PDF]

, 2013
Context: There is still some debate about the presence and the morphological properties of the long bar in the inner Galaxy. Aims: We investigate the morphological properties of the long Galactic bar using the VVV survey extending star counts at least ...
Amôres, Eduardo, González-Fernández, Carlos, Gurovich, Sebastian, López-Corredoira, Martín, Minniti, Dante, Moitinho, André   +5 more
core   +2 more sources

Gamma-Ray Astrophysics in the Time Domain

Galaxies, 2019
The last few years have seen gamma-ray astronomy maturing and advancing in the field of time-domain astronomy, utilizing source variability on timescales over many orders of magnitudes, from a decade down to a few minutes and shorter, depending on the ...
Frank M. Rieger
doaj   +1 more source

The Cosmic Origins Spectrograph and the Future of Ultraviolet Astronomy [PDF]

, 2009
I describe the capabilities of the Cosmic Origins Spectrograph, scheduled for May 2009 installation on the Hubble Space Telescope. With a factor-of-ten increase in far-UV throughput for moderate resolution spectroscopy, COS will enable a range of ...
George Sonneborn, H. Warren Moos, J. Michael Shull, Michael E. Van Steenberg, William P. Blair   +4 more
core   +1 more source