Scientific paper in Nature using the Monitor of MAXI on Kibo and the Swift satellite (USA) observations



August 25, 2011 (JST)

Scientific paper in Nature using
the Monitor of All-sky X-ray Image (MAXI) on Kibo and
the Swift satellite (USA) observations
– First observation of a massive black hole swallowing a star –

The Monitor of All-sky X-ray Image (MAXI) on Kibo, in coordination with the
gamma-ray burst satellite Swift (USA), observed the instant that a massive
black hole swallowed a star for the first time in the world, located in the
center of a galaxy 3.9 billion light years away. This result was published in
Nature online, issued on August 25 Japan time. The title of the paper is
“Relativistic Jet Activity from the Tidal Disruption of a Star by a Massive
Black Hole”.



Firetrench Directory

The Swift team, led by Prof. David Burrows of Penn State University, who is
also the main author of this paper, detected a strong gamma ray coming from the
object located in Draco constellation with a BAT instrument at 21:57 on March
28, 2011 (JST). This object, named Swift J1644+57, continued strong X-ray
emissions, so we understood it as different from a gamma-ray burst, as is often
observed when a massive star dies and a black hole is born.

Alerted by information from the Swift team, the MAXI team, including JAXA,
Riken, and Profs. Nobuyuki Kawai in Tokyo Tech and Hitoshi Negoro in Nihon
University, both of whom co-authored the Nature paper, reviewed the MAXI data
of this object and found that MAXI had detected X-rays from Swift J1644+57
several hours before the Swift discovery. They also found that there had been
no previous X-ray emission before the activity this time.

Detailed analysis of MAXI and Swift observations revealed that the X-ray came
from a black hole located in the center of a galaxy sucking down a star. This
was the first time that a nucleus with no X-ray emission had ever suddenly
started such activity. The strong X-ray and rapid variation indicated that the
X-ray came from a jet. Although there have been some other observations to
date, namely considered to be tidal disruption and a black hole swallowing a
star, they were not as violent as seen this time, and the beginning had not
previously been observed.

MAXI was mounted on the Japanese experimental module Kibo on the ISS in July
2009 and has been monitoring the whole sky since August 2009. Moreover, MAXI
can not only detect transient objects, but is also capable of investigating the
state of objects prior to the phenomenon, which led to the current discovery.
The X-ray camera with MAXI can detect low-energy X-rays, enabling wide-ranging
coverage when combined with Swift BAT. Continual monitoring of MAXI will lead
to further new discoveries in future.

“Relativistic Jet Activity from the Tidal Disruption of a Star by a Massive
Black Hole”
(10.1038/nature10374) by David Burrows (Penn State University, USA)

Co-authors in the MAXI team:
Nobuyuki Kawai, Ryuichi Usui (Tokyo Tech)
Mutsumi Sugizaki (Riken)
Yoshihiro Ueda, Kazuo Hiroi (Kyoto University)
Hitoshi Negoro (Nihon University)

Home page of MAXI

Home page of Swift

X-ray Image of Swift J1644+57 by MAXI

Significant result by MAXI
Since MAXI started all-sky X-ray observation on Kibo’s Exposed Facility in
August 2009, it has discovered many unexpected celestial X-ray events, and
provided global alerts of the same. In addition to the X-ray flares of stars
or X-ray novae caused by black holes and neutrons in our Galaxy, MAXI has
detected X-rays from Active Galactic Nuclei (AGNs) or gamma-ray bursts several
billion light years away. MAXI has been notifying them as alerts to astronomers
via the Internet. MAXI has also detected some unknown objects such as MAXI
J1659-152 (black hole binary) and MAXI J1409-619 (X-ray pulsar).

Related Links:
NASA Press Release



Japan Aerospace Exploration Agency (JAXA)
Institute of Physical and Chemical Research (RIKEN)
Publisher :
Public Affairs Department
Japan Aerospace Exploration Agency (JAXA)
Marunouchi Kitaguchi Building,
1-6-5, Marunouchi, Chiyoda-ku, Tokyo 100-8260 Japan

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