Dr. Stefan Immler
The New Scientist article Enigmatic object baffles supernova team said
An astronomical enigma has been spotted by a team hunting for very distant supernovas for their studies of the early universe.
At first glance, the object discovered on 22 February in the constellation Bootes resembled an ordinary supernova. But it kept growing brighter for much too long, and its spectrum was abnormal…
“It’s a very intriguing object”, says supernova researcher Stefan Immler of the NASA Goddard Space Flight Center in Maryland, US, but he will not rule out the possibility that it might be a supernova.
If it was extremely distant, the expansion of the Universe would relativistically stretch a supernova explosion. We would see a 20-day event stretched to 100 days at a red shift of 4, corresponding to an object about 12 billion light years away seen just 1.5 billion years after the big bang.
That would require an extremely bright supernova, but Immler says that such young stars would explode differently because they contain fewer heavy elements than modern stars.
Dr. Stefan Immler
is an astrophysicist at NASA’s
Goddard Space
Flight Center
(with
USRA), a support scientist in the
XMM-Newton
Guest Observer Facility and a duty scientist in the
SWIFT
Science Center. He is a member of the
Ask
an Astronomer
project and teaches cosmology at the University of Maryland.
His research is focused on astronomical objects with temperatures of some
million of degrees produce
radiation predominantly in the X-ray range (photon
energies: 0.1 to 100
keV). His projects are aimed at providing a comprehensive insight into
the
high-energy
astrophysical processes taking place in galaxies. Since the
Earth’s atmosphere is not transparent for incident X-rays, all
observations in the X-ray band must be performed with telescopes and
detectors onboard orbiting X-ray observatories high above the Earth’s
atmosphere. The most important X-ray astronomy missions currently used by
astronomers are the NASA X-ray mission
Chandra
and the ESA space mission
XMM-Newton. Ground- and
space-based observations obtained in other wavelength regimes (e.g. radio,
optical, UV) are used to supplement his X-ray data.
The emphasis of his studies is on the X-ray emission
components in nearby galaxies. X-ray observations of these galaxies are
used to study both the discrete X-ray source population (e.g.
X-ray
binaries, intermediate-mass
black holes,
supernova remnants, etc) and the
diffuse emission component (e.g., hot gas from within the disk and halo of
the galaxies). The detections of outflow of hot gas from the disk into the
halo of galaxies further enables us to study the dynamical processes that
lead to significant heating and enrichment of gas across the disk with
heavy elements (due to
star formation activities and multiple supernova
explosions). Enigmatic
ultraluminous X-ray sources were found within
some of the studied galaxies. Given the extremely high X-ray luminosities,
the short-term variability and their broadband spectral properties, these
X-ray sources most likely represent intermediate-mass black hole X-ray
binaries located in the spiral arms of the galaxies.
Stefan coauthored
Chandra Detection of a Hot Gaseous Corona around the Edge-on Galaxy
NGC 4631,
An Ultradeep High-Resolution X-Ray Image of M101: The X-Ray Source
Population in a Late-Type Spiral,
X-ray constraints on ionizing photons from accreting black holes at
Z~6,
X-Ray Supernovae, and
X-Ray, Optical, and Radio Observations of the Type II Supernovae 1999em
and 1998S.
Stefan earned a BSc and a MSc in Physics and Astronomy from the
Imperial College of Science, Technology & Medicine, London, UK in
1992,
did research in space sciences at the
Space Science Center, Institute for the Study of Earth,
Oceans and Space,
University of New Hampshire, Durham, NH in 1993,
earned a MSc in Physics from the
Ludwig-Maximilians-Universität München, Germany in 1996, and
a Ph.D. in astrophysics from the
Ludwig-Maximilians-Universität München, Germany in
2000.
Watch his
X-Ray
Emission from Supernovae in the SWIFT, Chandra and XMM-Newton Era
talk!