Dr. Martin S. Elvis
Martin S. Elvis, Ph.D.
is Senior Astrophysicist, Smithsonian
Astrophysical Observatory.
Born in the UK, and following degrees at the Universities of
Bristol and Sussex, Martin got his Ph.D. under Professor
Ken Pounds at the
University of Leicester (UK) in 1978 for work with the Ariel
V satellite. Ariel V was only the 2nd satellite to be devoted
to X-ray astronomy. While doing his Ph.D. he discovered the brightest
X-ray source ever seen in the sky, apart from the sun. (That sounds
easy, but it was a “transient” source,
A0620–00, and was really faint at the time. A0620–00 turns
out to be the nearest black hole known to date.) His
Ph.D.
thesis demonstrated that powerful X-ray emission was a
normal feature of Active Galactic Nuclei (or “AGN”). AGN X-ray
emission has been a lively area of research ever since.
He moved to the USA full time in 1980 to work on the first true X-ray
telescope, the Einstein
Observatory, at the Smithsonian Astrophysical Observatory in
Cambridge, Massachusetts, under
Riccardo Giacconi. He worked on many aspects of the Einstein
mission, and used the imaging power of Einstein to derive the first
X-ray spectra of quasars, the more powerful cousins of AGN,
and to discover extended
X-ray nebulae around nearby AGN, and a peculiar class of
galaxy that shows activity only in X-rays (now called ‘XBONGS’). With
Andrew Lawrence he proposed in 1982 that much of the confusion in the
classification of the AGN “zoo” was due to a flattened obscuring
region of dust and gas (Lawrence
and Elvis 1982). This was confirmed and extended by the
spectacular polarization study of Antonucci and Miller just 3 years
later, which is now the basis of the “Unified Scheme” for AGN.
This work is still active, because the obscuring torus does not seem
like a natural structure. In a recent paper (with A. Lawrence) he
suggests that tilted accretion disks could replace the standard
“donut” model of obscuration.
With the demise of the Einstein Observatory in 1981, he pursued
AGN
at all other wavelengths using a wide variety of telescope (IUE,
IRAS, IRTF, MMT, VLA, UKIRT, JCMT) leading, among other works, to the
1994
Atlas of Quasar Energy Distributions, which has served as
a standard since and has been cited almost 1,000 times. With the
revival of imaging X-ray astronomy on the 1990 launch of ROSAT and
then ASCA, he pushed studies of AGN and quasars to
high redshifts and extreme properties. Applying the
multi-wavelength approach to ROSAT spectra and ultraviolet spectra he,
with his colleagues, discovered a hot wind from a number of AGN,
peaking in 1995 with a UV/X-ray study of the “Seyfert galaxy”
NGC 5548.
In 1991 he began to work at the
Chandra X-ray Center (CXC), concentrating on the scientific
software needs of this revolutionary new observatory (then called
AXAF). After 1995 this work prevented him pursuing his normal program
of observations, and left him to contemplate AGN winds over and over
again. The result was a model for the structure
of quasars that unites into a simple picture much of the 10,000
papers worth of confusing knowledge about the emission and absorption
features in their spectra. This model has survived a number of tests
over the past few years, so there may actually be something to it. It
has been cited over 1,000 times. This model of the “Quasar Atmosphere”
remains a major focus of his research.
In 2007 he stepped down from his management position at the CXC, in
order to promote new missions that can greatly exceed Chandra in their
potential for revolutionary discoveries, and to work more with
students, one of whom is trying to make his 1994 “Atlas”
obsolete. Unable to not chase a good idea, he has also worked on the
Warm-Hot Intergalactic Medium, the physics of feedback by AGNs to
their host galaxies, and led the Chandra COSMOS wide/deep survey
project.
The change of direction for the human space program at NASA —
from
the Moon to asteroids as the first step towards Mars — seemed to
him
to offer a strategic potential for cheaper, larger space
observatories. He has begun to work on near-Earth asteroids (NEOs)
—
their detection and their properties — with a view to helping
NASA’s
exploration forward. Eventually, he is convinced, the commercial
potential of the asteroids will transform our space endeavors to a
truly large-scale, and will, in the process, make access to space cheap
and routine.
Martin has published over 300 papers in refereed journals and, with
over 15,000 citations, is one of the 250 most Highly Cited Researchers
in astronomy and space physics, as determined by
ISI.
Highlights
- Discovered that Active Galaxies were strong X-ray sources.
- Proposed first Unified Model for Active Galaxy types using a flattened “torus”.
- Atlas of quasar spectral energy distributions became the standard in the field.
- Developed the “funnel wind” model of Active Galaxies, unifying their phenomenology.
Read Extrasolar Asteroid Mining as Forensic Evidence for Extraterrestrial Intelligence, Asteroid-bound: Scientists look for a worthy rock: proximity and slow spin rate are desirable for exploration, Active Galaxies and Quasars, 2010–2020, The Most Luminous Stellar Nurseries in the Universe, A Black Hole Slingshot?, The “Eye of Sauron”, and Chandra sees Remarkable Eclipse of Black Hole.
