The Phoenix galaxy as seen by NuSTAR

¹ INAF–Osservatorio Astronomico di Bologna, via Ranzani 1, 40127 Bologna, Italy
e-mail: alberto.masini4@unibo.it
² Dipartimento di Fisica e Astronomia (DIFA), Università di Bologna, viale Berti Pichat 6/2, 40127 Bologna, Italy
³ ASDC-ASI, via del Politecnico, 00133 Roma, Italy
⁴ INAF–Osservatorio Astronomico di Roma, via Frascati 33, 00040 Monte Porzio Catone, Italy
⁵ Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125, USA
⁶ Centre for Extragalactic Astronomy, Department of Physics, University of Durham, South Road, Durham DH1 3LE, UK
⁷ School of Physics and Astronomy, University of Southampton, Highfield, Southampton SO17 1BJ, UK
⁸ Institute of Space and Astronautical Science (JAXA), 3-1-1 Yoshinodai, Sagamihara, 252-5252 Kanagawa, Japan
⁹ European Space Astronomy Center of ESA, PO Box 78, Villanueva de la Cañada, 28691 Madrid, Spain
¹⁰ Instituto de Astrofísica and Centro de Astroingeniería, Facultad de Física, Pontificia Universidad Católica de Chile, Casilla 306, Santiago 22, Chile
¹¹ Millennium Institute of Astrophysics (MAS), Nuncio Monseñor Sótero Sanz 100, Providencia, Santiago, Chile
¹² Space Science Institute, 4750 Walnut Street, Suite 205, Boulder, Colorado 80301, USA
¹³ EMBIGGEN Anillo, Concepción, Chile
¹⁴ Space Science Laboratory, University of California, Berkeley, CA 94720, USA
¹⁵ DTU Space National Space Institute, Technical University of Denmark, Elektrovej 327, 2800 Lyngby, Denmark
¹⁶ Lawrence Livermore National Laboratory, Livermore, CA 94550, USA
¹⁷ Department of Physics, Virginia Tech, Blacksburg, VA 24061, USA
¹⁸ Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027, USA
¹⁹ Institute for Astronomy, Department of Physics, ETH Zurich, Wolfgang-Pauli-Strasse 27, 8093 Zurich, Switzerland
²⁰ NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA
²¹ Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
²² Space Radiation Laboratory, California Institute of Technology, Pasadena, CA 91125, USA

Received: 1 August 2016
Accepted: 1 September 2016

Abstract

Aims. We study the long-term variability of the well-known Seyfert 2 galaxy Mrk 1210 (also known as UGC 4203, or the Phoenix galaxy).

Methods. The source was observed by many X-ray facilities in the last 20 yr. Here we present a NuSTAR observation and put the results in the context of previously published observations.

Results. NuSTAR observed Mrk 1210 in 2012 for 15.4 ks. The source showed Compton-thin obscuration similar to that observed by Chandra, Suzaku, BeppoSAX and XMM-Newton over the past two decades, but different from the first observation by ASCA in 1995, in which the active nucleus was caught in a low flux state or was obscured by Compton-thick matter with a reflection-dominated spectrum. Thanks to the high-quality hard X-ray spectrum obtained with NuSTAR and exploiting the long-term spectral coverage spanning 16.9 yr, we can precisely disentangle the transmission and reflection components and put constraints on both the intrinsic long-term variability and hidden nucleus scenarios. In the former case, the distance between the reflector and the source must be at least ~2 pc, while in the latter the eclipsing cloud may be identified with a water maser-emitting clump.