Browsing by Author "Neilsen, Joseph"

Now showing items 1-3 of 3

    • Discovery of an Ultraviolet Counterpart to an Ultra-Fast X-ray Outflow in the Quasar PG1211+143 

      Kriss, Gerard A.; Lee, Julia C.; Danehkar, Ashkbiz; Nowak, Michael A.; Fang, Taotao; Hardcastle, Martin J.; Neilsen, Joseph; Young, Andrew (2018-02-02)
      We observed the quasar PG 1211+143 using the Cosmic Origins Spectrograph on the Hubble Space Telescope in 2015 April as part of a joint campaign with the Chandra X-ray Observatory and the Jansky Very Large Array. Our ...

    • The High Energy X-ray Probe (HEX-P): probing accretion onto stellar mass black holes 

      Connors, Riley M. T.; Tomsick, John A.; Draghis, Paul; Coughenour, Benjamin; Shaw, Aarran W.; García, Javier A.; Walton, Dominic; Madsen, Kristin; Stern, Daniel; Rodriguez, Nicole Cavero; Dauser, Thomas; Del Santo, Melania; Jiang, Jiachen; Krawczynski, Henric; Liu, Honghui; Neilsen, Joseph; Nowak, Michael; Pike, Sean; Santangelo, Andrea; Sridhar, Navin; West, Andrew; Wilms, Jörn (2024-01-08)
      Accretion is a universal astrophysical process that plays a key role in cosmic history, from the epoch of reionization to galaxy and stellar formation and evolution. Accreting stellar-mass black holes in X-ray binaries are ...

    • The Ultra-Fast Outflow of the Quasar PG 1211+143 as Viewed by Time-Averaged Chandra Grating Spectroscopy 

      Danehkar, Ashkbiz; Nowak, Michael A.; Lee, Julia C.; Kriss, Gerard A.; Young, Andrew J.; Hardcastle, Martin J.; Chakravorty, Susmita; Fang, Taotao; Neilsen, Joseph; Rahoui, Farid; Smith, Randall K. (2018-02-02)
      We present a detailed X-ray spectral study of the quasar PG 1211+143 based on Chandra High Energy Transmission Grating Spectrometer (HETGS) observations collected in a multi-wavelength campaign with UV data using the Hubble ...