Browsing by Author "Gallo, Luigi C."

Browsing by Author "Gallo, Luigi C."

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  • Gallo, Luigi C.; MacMackin, C.; Vasudevan, R.; Cackett, E. M.; Fabian, A. C.; Panessa, F. (Oxford University Press, 2013-07)

    1ES 1927+654 is an active galactic nucleus (AGN) that appears to defy the unification model. It exhibits a type-2 optical spectrum, but possesses little X-ray obscuration. XMM–Newton and Suzaku ...


  • Gallo, Luigi C.; Fabian, A. C.; Zoghbi, A.; Wilkins, D. R.; Dwelly, T.; Uttley, P.; Schartel, N.; Miniutti, G.; Grupe, D.; Komossa, S. (Oxford University Press, 2012)
    The narrow-line Seyfert 1 Galaxy 1H 0707−495 went into a low state from 2010 December to 2011 February, discovered by a monitoring campaign using the X-Ray Telescope on the Swift satellite. We triggered a 100 ks XMM–Newton ...

  • Gallo, Luigi C.; Turner, David Gerald, 1945-; Majaess, Daniel J.; Lane, D. J.; Gieren, W.; Bonatto, C.; Balam, D.; Berdnikov, L. (American Astronomical SocietyIOP Publishing, 2012-07-10)
    New X-ray (XMM-Newton) and JHK[subscript s] (Observatoire du Mont-Megantic) observations for members of the star cluster Alessi 95, which Turner et al. discovered hosts the classical Cepheid SU Cas, were used in tandem ...

  • Smith, R. K.; Abraham, M.; Allured, R.; Bautz, M.; Bookbinder, J.; Bregman, J.; Brenneman, L.; Brickhouse, N. S.; Burrows, D.; Burwitz, V.; Cheimets, P. N.; Costantini, E.; Dawson, S.; DeRoo, C.; Falcone, A.; Foster, A. R.; Gallo, Luigi C.; Grant, C. E.; Günther, H. M.; Heilmann, R. K; Hertz, E.; Hine, B.; Huenemoerder, D.; Kaastra, J. S.; Kreykenbohm, I.; Madsen, K. K.; McEntaffer, R.; Miller, E.; Miller, J.; Morse, E.; Mushotzky, R.; Nandra, K.; Nowak, M.; Paerels, F.; Petre, R.; Poppenhaeger, K.; Ptak, A.; Reid, P.; Sanders, J.; Schattenburg, M.; Schulz, N.; Smale, A.; Temi, P.; Valencic, L.; Walker, S.; Willingale, R.; Wilms, J.; Wolk, S. J. (Society of Photo-Optical Instrumentation Engineers, 2017-08-29)
    Arcus, a Medium Explorer (MIDEX) mission, was selected by NASA for a Phase A study in August 2017. The observatory provides high-resolution soft X-ray spectroscopy in the 12-50Å bandpass with unprecedent-ed sensitivity: ...

  • Takahashi, Tadayuki; Kokubun, Motohide; Mitsuda, Kazuhisa; Kelley, Richard; Ohashi, Takaya; Aharonian, Felix; Akamatsu, Hiroki; Akimoto, Fumie; Allen, Steve; Anabuki, Naohisa; Gallo, Luigi C.; Wilkins, D. R. (SPIE International Society for Optical Engineering, 2016)
    The Hitomi (ASTRO-H) mission is the sixth Japanese X-ray astronomy satellite developed by a large international collaboration, including Japan, USA, Canada, and Europe. The mission aimed to provide the highest energy ...

  • Takahashi, Tadayuki; Mitsuda, Kazuhisa; Kelley, Richard; Aharonian, Felix; Akamatsu, Hiroki; Akimoto, Fumie; Allen, Steve; Anabuki, Naohisa; Angelini, Lorella; Arnaud, Keith; Gallo, Luigi C.; Wilkins, D. R. (Society of Photo Optical Instrumental Engineers, 2014-12-03)
    The joint JAXA/NASA ASTRO-H mission is the sixth in a series of highly successful X-ray missions developed by the Institute of Space and Astronautical Science (ISAS), with a planned launch in 2015. The ASTRO-H mission is ...

  • Gallo, Luigi C.; Bonson, K.; Fabian, A. C.; Grupe, D.; Komossa, S.; Longinotti, A. L.; Miniutti, G.; Walton, D. J.; Zoghbi, A.; Mathur, S. (Oxford University Press, 2013-01)
    As part of a long-term monitoring campaign of Mrk 335, deep XMM–Newton observations catch the narrow-line Seyfert 1 galaxy (NLS1) in a complex, intermediate flux interval as the active galaxy is transiting from low to high ...

  • Wilkins, D. R.; Kara, E.; Fabian, A. C.; Gallo, Luigi C. (Oxford University Press, 2014-09-21)
    The X-ray spectra of the narrow-line Seyfert 1 galaxy, 1H 0707–495, obtained with XMM–Newton, from time periods of varying X-ray luminosity are analysed in the context of understanding the changes to the X-ray ...

  • Wilkins, D. R.; Gallo, Luigi C. (Oxford University Press, 2015-03-21)
    We consider the Comptonization of the photons that make up the relativistically blurred reflection that is commonly detected from the accretion discs of active galactic nuclei by the coronae of energetic particles believed ...

  • Bonson, Kirsten (Halifax, N.S. : Saint Mary's University, 2017)
    The field of high-energy AGN astrophysics is about to be transformed as data of unprecedented quality and quantity will be arriving from the next-generation of X-ray observatories. With the advancement of technology, we ...

  • Bonson, Kirsten (Halifax, N.S. : Saint Mary's University, 2013)
    This work presents a deep analysis of HE 0436-4717: a “bare” Seyfert 1 galaxy with strong variability and moderate soft excess. Data included a 200 ks observation with XMM-Newton EPIC instruments, a Swift BAT detection up ...

  • Duelge, Larkin Michelle (Halifax, N.S. : Saint Mary's University, 2011)
    The XMM-Newton Observatory has conducted many observations of the type I active galactic nucleus 1H0707-495. The 0.7 deg [superscript 2] field of view around the AGN was observed over the course of ∼10 years with a total ...

  • LaMassa, Stephanie M.; Cales, Sabrina; Moran, Edward C.; Myers, Adam D.; Richards, Gordon T.; Eracleous, Michael; Heckman, Timothy M.; Gallo, Luigi C.; Urry, C. Megan (American Astronomical Society, 2015-02-20)
    SDSS J015957.64+003310.5 is an X-ray selected, z = 0.31 active galactic nucleus (AGN) from the Stripe 82X survey that transitioned from a Type 1 quasar to a Type 1.9 AGN between 2000 and 2010. This is the most distant AGN, ...

  • Wilkins, D. R.; Gallo, Luigi C. (Oxford University Press, 2015-05-01)
    Variations in the X-ray emission from the narrow-line Seyfert 1 galaxy, Markarian 335, are studied on both long and short time-scales through observations made between 2006 and 2013 with XMM–Newton, Suzaku and NuSTAR. ...

  • Gonzalez, Adam (Halifax, N.S. : Saint Mary's University, 2017)
    The differences in emissivity profiles produced by various corona geometries are explored via general relativistic ray tracing simulations in order to better understand the inner disc region of active galactic nuclei. ...

  • Wilkins, D. R.; Gallo, Luigi C.; Grupe, D.; Bonson, K.; Komossa, S.; Fabian, A. C. (Oxford University Press, 2015-12-21)
    Monitoring of the narrowline Seyfert 1 galaxy Markarian 335 (Mrk 335) with the Swift satellite discovered an X-ray flare beginning 2014 August 29. At the peak, the 0.5–5 keV count rate had increased from that in the low-flux ...

  • Ehler, Hannah (Halifax, N.S. : Saint Mary's University, 2017)
    Markarian 335, a Narrow-Line Seyfert 1 Galaxy, has been one the brightest X-ray sources in the sky until 2007 when its flux dropped to 1/10th of its previous value. Despite this dramatic decrease, Mrk 335 still remains one ...

  • Vasudevan, Ranjan V.; Mushotzky, Richard F.; Reynolds, Christopher S.; Fabian, Andrew C.; Lohfink, Anne M.; Zoghbi, Abderahmen; Gallo, Luigi C.; Walton, Dominic (IOP Publishing Limited, 2014-04-10)
    The X-ray spectra of many active galactic nuclei exhibit a “soft excess” below 1 keV, whose physical origin remains unclear. Diverse models have been suggested to account for it, including ionized reflection ...

  • Gallo, Luigi C.; Fabian, A. C. (Oxford University Press on behalf of the Royal Astronomical Society, 2011-11)
    Narrow absorption lines seen in the 2–10 keV spectra of active galaxies and Galactic black holes are normally attributed to iron in high-velocity outflows or inflows. We consider the possibility that such features could ...

  • Bonson, K.; Gallo, Luigi C. (Oxford University Press, 2016-05-11)
    Being one of only two fundamental properties black holes possess, the spin of supermassive black holes (SMBHs) is of great interest for understanding accretion processes and galaxy evolution. However, in these early days ...