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Browsing by Author "Ely, J. C."

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    A fast and long-lived outflow from the supermassive black hole in NGC 5548
    Kaastra, J. S.; Kriss, G. A.; Cappi, M.; Mehdipour, M.; Petrucci, P. O.; Steenbrugge, K. C.; Arav, Nahum; Behar, E.; Bianchi, S.; Boissay, R.; Branduardi-Raymont, G.; Chamberlain, C.; Costantini, E.; Ely, J. C.; Ebrero, J.; Di Gesu, L.; Harrison, F. A.; Kaspi, S.; Malzac, J.; De Marco, B.; Matt, G.; Nandra, K.; Paltani, S.; Person, R.; Peterson, B. M.; Pinto, C.; Ponti, G.; Nunez, F. P.; De Rosa, A.; Seta, H.; Ursini, F.; de Vries, C. P.; Walton, D. J.; Whewell, M. (Amer Assoc Advancement Science, 2014-07-04)
    Supermassive black holes in the nuclei of active galaxies expel large amounts of matter through powerful winds of ionized gas. The archetypal active galaxy NGC 5548 has been studied for decades, and high-resolution X-ray and UV observations have previously shown a persistent ionized outflow. An observing campaign in 2013 with six space observatories shows the nucleus to be obscured by a long-lasting, clumpy stream of ionized gas never seen before. It blocks 90% of the soft X-ray emission and causes simultaneous deep, broad UV absorption troughs. The outflow velocities of this gas are up to five times faster than those in the persistent outflow, and at a distance of only a few light days from the nucleus, it may likely originate from the accretion disk.
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    Multiwavelength campaign on Mrk 509: XVI. Continued HST/COS monitoring of the far-ultraviolet spectrum
    Kriss, G. A.; Arav, Nahum; Edmonds, Douglas; Ely, J. C.; Kaastra, J. S.; Bianchi, S.; Cappi, M.; Costantini, E.; Ebrero, J.; Mehdipour, M.; Paltani, S.; Petrucci, P. O.; Ponti, G. (EDP Sciences, 2019-03-07)
    Aims. To elucidate the location, physical conditions, mass outflow rate, and kinetic luminosity of the outflow from the active nucleus of the Seyfert 1 galaxy Mrk 509, we used coordinated UV and X-ray spectral observations in 2012 to follow up our lengthier campaign conducted in 2009. Methods. We observed Mrk 509 with the Cosmic Origins Spectrograph (COS) on the Hubble Space Telescope (HST) on 2012-09-03 and 2012-10-11 coordinated with X-ray observations using the High Energy Transmission Grating on the Chandra X-ray Observatory. Our far-ultraviolet spectra used grating G140L on COS to cover wavelengths from 920-2000 Å at a resolving power of ∼2000, and gratings G130M and G160M to cover 1160-1750 Å at a resolving power of ∼15, 000. Results. We detect variability in the blueshifted UV absorption lines on timescales spanning 3-12 years. The inferred densities in the absorbing gas are greater than log n cm -3 ∼ 3. For ionization parameters ranging over log U =-1.5 to-0.2, we constrain the distances of the absorbers to be closer than 220 pc to the active nucleus. Conclusions. The impact on the host galaxy appears to be confined to the nuclear region. © 2019 G. A. Kriss et al.