Zobrazeno 1 - 10
of 40
pro vyhledávání: '"Wargelin, B. J."'
Autor:
Wargelin, B. J., Saar, S. H., Irving, Z. A., Slavin, J. D., Ratzlaff, P., Nascimento Jr, J. -D. do
Proxima Cen (GJ 551; dM5.5e) is one of only about a dozen fully convective stars known to have a stellar cycle, and the only one to have long-term X-ray monitoring. A previous analysis found that X-ray and mid-UV observations, particularly two epochs
Externí odkaz:
http://arxiv.org/abs/2411.04252
Stars of stellar type later than about M3.5 are believed to be fully convective and therefore unable to support magnetic dynamos like the one that produces the 11-year solar cycle. Because of their intrinsic faintness, very few late M stars have unde
Externí odkaz:
http://arxiv.org/abs/1610.03447
We present results from two Chandra imaging observations of Ross 154, a nearby flaring M dwarf star. During a 61-ks ACIS-S exposure, a very large flare occurred (the equivalent of a solar X3400 event, with L_X = 1.8x10^30 ergs/s) in which the count r
Externí odkaz:
http://arxiv.org/abs/0712.2791
The past decade has seen a surge of interest in astrophysical charge exchange (CX). The impetus was the discovery of X-ray emission from comets in 1996, soon followed by the observation of CX emission in planetary atmospheres and throughout the helio
Externí odkaz:
http://arxiv.org/abs/0708.0233
Publikováno v:
Astrophys.J.634:687-697,2005
We present H-like Fe XXVI and He-like Fe XXV charge-exchange spectra resulting from collisions of highly charged iron with N2 gas at an energy of 10 eV/amu in an electron beam ion trap. Although individual high-n emission lines are not resolved in ou
Externí odkaz:
http://arxiv.org/abs/astro-ph/0508078
Autor:
Desai, P., Brickhouse, N. S., Drake, J. J., Dupree, A. K., Edgar, R. J., Hoogerwerf, R., Kashyap, V., Wargelin, B. J., Smith, R. K., Huenemoerder, D. P., Liedahl, D. A.
Publikováno v:
Astrophys.J. 625 (2005) L59-L62
Observations of Fe XVIII and Fe XIX X-ray, EUV, and FUV line emission, formed at the peak of Capella's (alpha Aurigae) emission measure distribution and ubiquitous in spectra of many cool stars and galaxies, provide a unique opportunity to test the r
Externí odkaz:
http://arxiv.org/abs/astro-ph/0503183
Publikováno v:
Astrophys.J. 623 (2005) 225-234
Chandra observations toward the nearby molecular cloud MBM12 show unexpectedly strong and nearly equal foreground O VIII and O VII emission. As the observed portion of MBM12 is optically thick at these energies, the emission lines must be formed near
Externí odkaz:
http://arxiv.org/abs/astro-ph/0501056
Publikováno v:
Astrophys.J. 607 (2004) 596-610
We have analyzed data from two sets of calibration observations of the Moon made by the Chandra X-ray Observatory. In addition to obtaining a spectrum of the bright side that shows several distinct fluorescence lines, we also clearly detect time-vari
Externí odkaz:
http://arxiv.org/abs/astro-ph/0402247
Autor:
Markevitch, M., Bautz, M. W., Biller, B., Butt, Y., Edgar, R., Gaetz, T., Garmire, G., Grant, C. E., Green, P., Juda, M., Plucinsky, P. P., Schwartz, D., Smith, R., Vikhlinin, A., Virani, S., Wargelin, B. J., Wolk, S.
Publikováno v:
Astrophys.J. 583 (2003) 70
We present an exploratory Chandra ACIS-S3 study of the diffuse component of the Cosmic X-ray Background in the 0.3-7 keV band for four directions at high Galactic latitudes, with emphasis on details of the ACIS instrumental background modeling. Obser
Externí odkaz:
http://arxiv.org/abs/astro-ph/0209441
Autor:
Drake, J. J., Marshall, H. L., Dreizler, S., Freeman, P. E., Fruscione, A., Juda, M., Kashyap, V., Nicastro, F., Pease, D. O., Wargelin, B. J., Werner, K.
Publikováno v:
Astrophys.J. 572 (2002) 996-1001
Deep Chandra LETG+HRC-S observations of the isolated neutron star candidate RX J1856.5-3754 have been analysed to search for metallic and resonance cyclotron spectral features and for pulsation behaviour. As found from earlier observations, the X-ray
Externí odkaz:
http://arxiv.org/abs/astro-ph/0204159