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Research of the Infrared/Submillimeter Group at MPE
Research of the Infrared and Submillimeter Group
is focused on the fields of evolution of galaxies and galactic nuclei,
including the center of our own Galaxy and starburst phenomena,
as well as studies of the dense interstellar medium in star- and
planet forming regions.
- Galactic nuclei
The Galactic Center Project
(see also dedicated  Galactic Center page)
Our own Galactic center provides an essential
laboratory for studying the black hole paradigm, and for a detailed
characterisation of a (comparatively small) nuclear stellar cluster.
Since 1992, we have used diffraction limited infrared imaging to study the
stellar dynamics of the central parsec and the influence of the central black
hole. Infrared spectroscopy characterises the stellar population evolving in
an environment that is unique in our Galaxy. Flared near-infrared emission
that we detected in 2003 is a unique way to probe the immediate vicinity of the
black hole.
Current group members involved:
Hendrik Bartko, Frank Eisenhauer, Tobias Fritz, Reinhard Genzel, Stefan Gillessen,
Reiner Hofmann, Dieter Lutz,
Thomas Ott, Sascha Trippe.
Former group members and/or collaborators:
Roberto Abuter, Andreas Eckart, Rainer Schoedel, Tal Alexander,
Alfred Krabbe, Rolf-Peter Kudritzki, Paco Najarro, Thibaut Paumard, Fabrice Martins
Key publications:
The Nuclear Cluster of the Milky Way: Star Formation and Velocity
Dispersion in the Central 0.5 Parsec, A.
Krabbe et al., ApJ 447, L95 (1995)
SWS Observations of the Galactic Center, D. Lutz et al., A&A
315, L269 (1996)
Stellar proper motions in the central 0.1pc of the Galaxy, A. Eckart
& R. Genzel, MNRAS 291, 219 (1997)
A star in a 15.2-year orbit around the supermassive black hole at the
centre of the Milky Way, R. Schödel et al., Nature 419, 694 (2002)
Near-infrared flares from accreting gas around the supermassive black
hole at the Galactic Centre, R. Genzel et al., Nature 425, 934 (2003)
SINFONI in the Galactic Center: Young Stars and Infrared Flares in the Central Light-Month,
F. Eisenhauer et al., ApJ 628, 246 (2005)
Ultraluminous Infrared Galaxies and QSOs
The
population of Ultraluminous Infrared
Galaxies (ULIRGs) plays a key role in scenarios for the formation of
Quasars
and of elliptical galaxies, and as possible local analogues to high
redshift
infrared sources. We are testing the energy sources of ULIRGs and QSOs
using
ISO and Spitzer mid-infrared spectroscopy and near-infrared imaging
spectroscopy. Dynamical studies using near-infrared spectroscopy and mm
interferometry probe the evolution from ULIRGs to (disky) ellipticals
and their
evolutionary conncetion to QSOs.
Current
group members involved: Alessandra
Contursi, Ric Davies, Reinhard
Genzel, Dieter Lutz,
Mario
Schweitzer,
Eckhard Sturm, Linda
Tacconi
Former group members and/or collaborators: Sylvain Veilleux, Alan
Moorwood,
Dave Sanders, Amiel Sternberg, Thorsten Naab, Andrew Baker,
Kalliopi
Dasyra, Eiichi Egami, Christof Iserlohe, Dimitra Rigopoulou, Henrik
Spoon,
Matthias Tecza, Dan Tran, Aprajita Verma, Paul van der Werf
Key publications:
Near-infrared line
imaging of
NGC 6240 - Collision shock and nuclear starburst, P. van der Werf et
al., ApJ 405,
522 (1993)
What Powers
Ultraluminous
IRAS Galaxies?, R.
Genzel et al., ApJ 498, 579 (1998)
The Nature and Evolution of Ultraluminous Infrared Galaxies: A
Mid-Infrared
Spectroscopic Survey, D. Lutz et al., ApJ, 505, L103 (1998)
Ultraluminous Infrared Mergers: Elliptical Galaxies in Formation? R.
Genzel et
al., ApJ 563, 527 (2001
Spitzer Quasar and ULIRG
Evolution Study (QUEST). I. The Origin of the Far-Infrared Continuum of
QSOs, M.
Schweitzer et al. ApJ 649, 79 (2006)
Starburst Galaxies and Young Clusters
A significant fraction of star formation
in the
local universe occurs in a few dusty galaxies with temporarily elevated
star
formation rates, that cannot be sustained over times comparable to the
age of
the universe. Similar objects are even more important at high redshift.
We are
using near- and mid-infrared spectroscopic diagnostics in conjunction
with
evolutionary synthesis and photoionization modelling to determine the
history
and stellar compositions of these burst events. High spatial resolution
observations are obtained to characterize the compact 'super star
clusters'
representing a major part of the new stars in starbursts. An
important
complement are direct high resolution studies of the lower end of the
Initial
Mass Function in Galactic and nearby extragalactic star
clusters.
Current group members
involved: Alessandra Contursi, Frank Eisenhauer, Natascha
Förster Schreiber,
Reinhard Genzel, Dieter Lutz, Fabrice Martins
Former group members and/or collaborators: Amiel Sternberg, Alan
Moorwood,
Rolf-Peter Kudritzki, Adi Pauldrach, Dan
Jaffe, Marco Barden, Bernhard Brandl, Frank Bertoldi, Peter Englmaier,
Andrea
Gilbert, Yohei Harayama, Alfred Krabbe, Harald Kroker, Dietmar Kunze,
Sabine
Mengel, Matt Lehnert, Leslie Looney, Emmanuel Moy, Dimitra Rigopoulou,
Bill
Vacca, Bruce Sams, Michele Thornley, Aprajita Verma
Key Publications:
Stellar Content of the Galactic Starburst Template NGC 3603 from
Adaptive
Optics Observations, F. Eisenhauer et al., ApJ 498, 278 (1998).
Massive Star Formation and
Evolution in Starburst Galaxies: Mid-infrared Spectroscopy with the ISO
Short
Wavelength Spectrometer, M. Thornley et al., ApJ 539, 641 (2000)
Dynamical masses of young star clusters in NGC 4038/4039, S. Mengel et
al.,
A&A 383, 137 (2002)
Nearby AGN and Black Holes
Several
open questions concerning active
galactic nuclei and their environment are best addressed by our tools
of high
spatial resolution near-infrared spectroscopy, mm interferometry and
mid-infrared spectroscopy. Among others, projects have dealt with
characterization of cirumnuclear starbursts, distribution and dynamics
of
circumnuclear gas, reconstruction of the AGN SED from photoionisation
modelling, and searches for obscured broad line regions. In quiescent
objects,
we are probing for the dynamical signature of non-active black holes
using high
spatial and spectral resolution near-infrared spectroscopy.
Current
group members involved: Ric Davies,
Reinhard Genzel, Erin
Hicks, Dieter Lutz, Francisco Mueller-Sanchez, Mario Schweitzer,
Eckhard Sturm,
Linda Tacconi
Former group members and/or collaborators: Tal
Alexander, Stefan Anders, Andrew Baker, Markus Blietz, Murray Cameron,
Andreas
Eckart, Jack Gallimore, Matt Lehnert, Roberto Maiolino, Alan Moorwood,
Hagai Netzer,
Tino Oliva, Andreas Quirrenbach, Eva Schinnerer, Amiel Sternberg,
Lowell
Tacconi-Garman, Niranjan Thatte, Lothar Weitzel
Key publications:
The nature of the dense obscuring material in the nucleus of NGC 1068,
L.
Tacconi et al., ApJ 426, L77 (1994)
Infrared imaging and spectroscopy of NGC 7469, R. Genzel et al., ApJ
444, 129
(1995)
2.5-45μm SWS spectroscopy of the Circinus Galaxy, A. Moorwood et
al., A&A
315, L109 (1996)
The
Star-forming Torus and Stellar Dynamical Black
Hole Mass in the Seyfert 1 Nucleus of NGC 3227, R. Davies et al. ApJ
646, 754
(2006)
- Evolution of Galaxies
Identification and Nature of High Redshift Infrared and Submm Sources
Surveys at mid-infrared and (sub)mm wavelengths
with ISO, SCUBA, MAMBO and Spitzer have uncovered populations of
massively star
forming galaxies at high redshift that constitute a major part of the
total
cosmic star forming activity and a key phase in the evolution of
massive
galaxies. We are carrying out several projects aiming at identifying
these objects,
studying their nature, and determining their relation to other objects
classes
like the Lyman Break galaxies representing the bulk of the unobscured
z~3
population.
Current group members involved:
Reinhard Genzel, Dieter Lutz,
Eckhard Sturm, Linda Tacconi,
Elisabetta Valiante
Former group members and/or collaborators: Karl Menten, Frank Bertoldi,
Chris
Carilli, James Dunlop, Dave Sanders, Lin Yan, Paola Andreani,
Andrew
Baker, Helmut Dannerbauer, Matt Lehnert, Emmanuel Moy, Dimitra
Rigopoulou,
Aprajita Verma
Key publications:
Properties of Millimeter Galaxies: Constraints from K-Band Blank
Fields, H.
Dannerbauer et al., ApJ 573, 473 (2002)
Spatially Resolved Millimeter Interferometry of SMM J02399-0136: A Very
Massive
Galaxy at z = 2.8, R. Genzel et al., ApJ 584, 663 (2003)
Interferometric Observations of Powerful CO Emission
from Three Submillimeter Galaxies at z=2.39, 2.51, and 3.35, R. Neri et
al.,
ApJ 597, L113 (2003)
Luminous
Lyman Break Galaxies at z>5 and the Source of Reionization, M.D.
Lehnert & M. Bremer, ApJ 593, 630 (2003)
Molecular
Gas in the lensed Lyman Break Galaxy cB58, A. Baker et al., ApJ 604,
125 (2004)
Dynamics and Evolution of Massive High Redshift Galaxies (see also dedicated
SINS page)
Determining the evolution of
massive galaxies with redshift
is a key long term goal in studying galaxy evolution and a crucial test
for
current hierarchical models. We have started to address this issue
using IRAM
mm interferometry of submm sources and Lyman Break galaxies, and are
now
studying a large sample representing several categories of
high redshift
galaxies using integral field spectroscopy with SINFONI at the VLT. We
are
obtaining spatially resolved measures of dynamics, metallicity, and
ionization
in order to determine the physical properties and relations of
these
different categories of high redshift galaxies.
Current
group members involved: Nicolas Bouche, Peter Buschkamp, Giovanni
Cresci, Ric
Davies, Frank Eisenhauer, Natascha Förster Schreiber, Shy
Genel, Stefan
Gillessen, Reinhard Genzel, Erin Hicks, Dieter Lutz, Linda Tacconi.
Former group members and/or collaborators: Chuck
Steidel, Alice
Shapley, Andrea Cimatti, Alvio Renzini, Simon Lilly, Andrew Blain,
Scott
Chapman, Rob Ivison, Ian Smail, Roberto Neri, Pierre Cox, Alain Omont,
Frank
Bertoldi, Andi Burkert, Thorsten Naab, Roberto Abuter, Andrew Baker,
Marco
Barden, Matt Lehnert, Nicole Nesvadba, Dimitra Rigopoulou, Kirsten
Shapiro, Matthias
Tecza, Aprajita Verma
Key publications:
SPIFFI Observations of the Starburst SMM J14011+0252: Already Old, Fat,
and
Rich by z=2.565, M. Tecza et al., ApJ 605, L109 (2004)
High Resolution Millimeter
Imaging of Submm Galaxies, L. Tacconi et al., ApJ, 640, 228
(2006)
SINFONI Integral Field
Spectroscopy of z ~ 2 UV-selected Galaxies: Rotation Curves and
Dynamical
Evolution, N.M. Förster Schreiber et al. ApJ 645, 1062 (2006)
- Studies of star formation and the (dense) interstellar medium
 Water in star-forming regions
Water is one of the most abundant and important molecules in star- and
planet-forming regions, not in the least because of its direct
association with the biology of living organisms on Earth. Although
only a trace species in general clouds, water becomes the third most
abundant molecule in the warm regions created by the presence of
newly-formed stars. In a Herschel guaranteed time
and open time program, we will use
the HIFI and PACS instruments to observe water towards a large sample
of protostars, covering a wide range of masses and luminosities -from
the lowest to the highest mass protostars-, and a large range of
evolutionary stages -from the first stages represented by the
pre-stellar cores to the last stages represented by pre-main sequence
stars surrounded only by protoplanetary disks. Prepatory and
complementary observations are carried out using the JCMT, APEX and
SMA submillimeter telescopes, and molecular excitation and radiative
transfer tools are being developed.
Current group members involved: Ewine van Dishoeck, Gregory Herczeg
Former group members and/or collaborators: Michiel Hogerheijde, Jes
Jorgensen, Tim van Kempen, Lars Kristensen, Umut Yildiz, the WISH team, Neal Evans, the DIGIT team
Key publications:
Water emission from low-mass protostellar envelopes,
T. van Kempen et al., A&A, 487, 975 (2008)
Warm molecular gas in the envelope and outflow of IRAS 12496-7650 (DK Cha),
T. van Kempen et al., A&A, 454, L75 (2006)
Probing the inner 200 AU of low-mass protostars with the Submillimeter
Array: dust and organic molecules in NGC 1333 IRAS 2A, J.K. Jorgensen et al.,
ApJ, 632, 973 (2005)
Molecular inventories and chemical evolution of low-mass protostellar
envelopes, J.K. Jorgensen et al., A&A 416, 603 (2004)
Structure and evolution of protoplanetary disks
Most young pre-main sequence stars are surrounded by disks of gas and
dust out of which planets can form. We are carrying out a number of
projects using infrared spectroscopy with VLT-CRIRES and Spitzer-IRS
(in particular through the "Cores to Disks" Legacy program),
far-infrared spectroscopy with Herschel (through the DIGIT key program),
and submillimeter imaging aimed
at understanding their physical and chemical structure and evolution.
Of particular interest are the transitional disks with large inner
holes, which are at the crucial stage in between the gas-rich and
debris-disk phases when planet formation appears to be actively
taking place.
Current group members involved: Ewine van Dishoeck, Joanna Brown, Gregory Herczeg
Former group members and/or collaborators: Jeanette Bast, Geoff Blake,
Kees Dullemond, Neal Evans, Vincent Geers, Fred Lahuis, Bruno Merin,
Isa Oliveira, Klaus Pontoppidan, Rachel Smith, Colette Salyk, the DIGIT team
Key publications:
Cold disks: Spitzer spectroscopy of disks around young stars with large gaps,
J.M. Brown et al. 2007, ApJ, 664, L107
Spatial separation of small and large grains in the transitional disk
around the young star IRS 48, V.C. Geers et al. 2007, A&A, 469, L35
Hot organic molecules toward a young low-mass star: a look at inner
disk chemistry, F. Lahuis et al. 2006, ApJ 636, L145
H2O and OH gas in the terrestrial zones of protoplanetary disks around
two classical T Tauri stars, C. Salyk et al., ApJ 676, L49
(2008)
© Infrared and Submillimeter Astronomy Group at MPE
last update:
20/10/2008, editor of this page: Dieter Lutz
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Research