A5011716303- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- Adaptive optics and wavefront sensing
- Astrophysical Phenomena and Observations
- Galaxies: Formation, Evolution, Phenomena
- Spectroscopy and Laser Applications
- Atmospheric Ozone and Climate
- Astrophysics and Cosmic Phenomena
- Astronomical Observations and Instrumentation
- Gamma-ray bursts and supernovae
- Radio Astronomy Observations and Technology
- Dark Matter and Cosmic Phenomena
- Astro and Planetary Science
- Calibration and Measurement Techniques
- Pulsars and Gravitational Waves Research
- Neutrino Physics Research
- Scientific Measurement and Uncertainty Evaluation
- Atomic and Molecular Physics
- Climate variability and models
- Molecular Spectroscopy and Structure
- Heat Transfer Mechanisms
- Solar and Space Plasma Dynamics
- Mechanics and Biomechanics Studies
- Scientific Computing and Data Management
University of Stuttgart
2009-2023
University of Cologne
2004-2014
University of California, Los Angeles
2013
Thüringer Landessternwarte Tautenburg
2009
University of Hawaii at Hilo
2009
Max Planck Institute for Extraterrestrial Physics
2002-2006
TH Köln - University of Applied Sciences
2006
Max Planck Society
2003-2004
Max Planck Innovation
2004
Universidad Complutense de Madrid
2002
SINFONI is an adaptive optics assisted near-infrared integral field spectrometer for the ESO VLT. The Adaptive Optics Module (built by Group) a 60-elements curvature-sensor based system, designed operations with natural or sodium laser guide stars. SPIFFI Infrared Group of MPE) provides simultaneous spectroscopy 32 x spatial pixels, and spectral resolving power up to 3300. module in phase integration; presently tested laboratory. We provide overview project, particular emphasis on problems...
232 hours of data were accumulated from 1997 to 1999, using the HEGRA Stereoscopic Cherenkov Telescope System observe supernova remnant Cassiopeia A. TeV γ-ray emission was detected at level, and a flux above 1 derived. The spectral distribution is consistent with power law differential index between 10 TeV. As this first report detection source on "centi-Crab"scale, we present analysis in some detail. Implications for acceleration cosmic rays depend details modeling. We discuss important...
We present new near-infrared (NIR) Keck and Very Large Telescope (VLT) spectroscopic data on the stellar dynamics in late-stage, ultraluminous infrared galaxy (ULIRG) mergers. now have information structural kinematic properties of 18 ULIRGs, eight which contain QSO-like active galactic nuclei (AGNs). The host (σ, reff, μeff, MK) AGN-dominated star formation dominated ULIRGs are similar. fall remarkably close to fundamental plane early-type galaxies. They populate a wide range plane, average...
We present an overview of the OSIRIS integral field spectrograph which was recently commissioned on Keck II Telescope. works with Adaptive Optics system and utilizes infrared transmissive lenslet array to sample a rectangular view at close diffraction limit. By packing spectra together (2 pixel rows per spectrum) using Rockwell Hawaii-2 detector (wavelengths between 1 2.5 microns), we achieve relatively large (up 6."4) while maintaining full broad-band spectral coverage resolution 3800....
We describe the design of Field-Imaging Far-Infrared Line Spectrometer (FIFI-LS), operated as a Facility-Class instrument on Stratospheric Observatory for Infrared Astronomy (SOFIA). FIFI-LS is an imaging spectrometer medium resolution spectroscopy. Since being commissioned in 2014, it has performed over 50 SOFIA commissioning and science flights. After operating principal investigator 2014 early 2015, was accepted Facility Science Instrument 2015. In addition to description design, we...
We present commissioning data from the OSIRIS integral field spectrograph (IFS) on Keck II 10 m telescope that demonstrate utility of adaptive optics IFS spectroscopy in studying faint close-in sub-stellar companions haloes bright stars. Our R~2000 J- and H-band spectra companion to 1-10 Myr-old GQ Lup complement existing K-band photometry, improve original estimate its spectral type. find B is somewhat hotter (M6-L0) than reported discovery paper by Neuhauser collaborators (M9-L4), mainly...
We present 0.1" resolution near-infrared integral field spectroscopy of Halpha in a z=1.4781 star forming galaxy, Q2343-BM133. These observations were obtained with OSIRIS (OH Suppressing Infra-Red Imaging Spectrograph) using the W.M. Keck Observatory Laser Guide Star Adaptive Optics system. emission is resolved over 0.8" (6.8 kpc) x 0.5" (4.3 region spatial resolution. find global flux 4.2+/-0.6x10^{-16} ergs s^{-1} cm^{-2}, and detect spatially velocity gradient ~134 km across galaxy...
ABSTRACT Determining the efficiency with which gas is converted into stars in galaxies requires an accurate determination of total reservoir molecular mass. However, despite being most abundant molecule Universe, H2 challenging to detect through direct observations and indirect methods have be used estimate reservoir. These are often based on scaling relations from tracers such as CO or dust, generally calibrated Milky Way. Yet, evidence that these environmentally dependent growing. In...
Data taken with the HEGRA system of imaging atmospheric Cherenkov telescopes during 1997 flares Markarian 501 (Mkn 501) are reanalyzed using an algorithm providing improved energy resolution. A resolution 10% to 12% is obtained by accounting for variation light yield height shower maximum in atmosphere. The particularly relevant study high-energy cutoff spectrum, which might be caused interactions intergalactic infrared background radiation. reanalysis presented here confirms results...
The IRS 13E complex is an unusual concentration of massive, early-type stars at a projected distance ~0.13 pc from the Milky Way's central supermassive black hole Sagittarius A* (Sgr A*). Because their similar proper motion and common nature as young stars, it has recently been suggested that may be remnant massive stellar cluster containing intermediate-mass (IMBH) binds its members gravitationally in tidal field Sgr A*. Here, we present analysis motions environment combines currently best...
During 1997, the BL Lac object Mkn 501 went into an extraordinary state of high X-ray and TeV gamma-ray activity, lasting more than 6 months. In this paper we report on emission characteristics source in subsequent years 1998 1999 as measured with Stereoscopic Cherenkov Telescope System HEGRA (La Palma, Canary Islands). Our observations reveal a 1998-1999 mean level at 1 1/3 flux Crab Nebula, factor 10 lower during year 1997. A dataset 122 hours telescope system makes it possible to assess...
The field-imaging far-infrared line spectrometer (FIFI-LS) is a science instrument for the Stratospheric Observatory Infrared Astronomy (SOFIA). FIFI-LS allows simultaneous observations in two spectral channels. “blue” channel sensitive from 51[Formula: see text][Formula: text]m to 125[Formula: and “red” 115[Formula: 203[Formula: text]m. instantaneous coverage 1000–3000[Formula: text]km/s blue 800–2500[Formula: red with resolution between 150[Formula: 600[Formula: text]km/s. Each observes...
In this article we present an analysis of possible science cases for NASA's Stratospheric Observatory Infrared Astronomy (SOFIA) in the field extrasolar planet detection and characterization. Advantages SOFIA its instruments exoplanet observations are illustrated targets introduced. Possible future instrumentation is discussed.
We present SOFIA/FIFI-LS observations of the [CII] 158${\mu}$m cooling line across nearby spiral galaxy NGC 6946. combine these with UV, IR, CO, and H I data to compare emission dust properties, star formation rate (SFR), H$_2$, HI at 560pc scales via stacking by environment (spiral arms, interarm, center), radial profiles, individual, beam-sized measurements. attribute $73\%$ luminosity $19\%$ $8\%$ center interarm region, respectively. [CII]/TIR, [CII]/CO, [CII]/PAH profiles are largely...
Using the HEGRA system of imaging atmospheric Cherenkov telescopes, a region Galactic plane (, ) was surveyed for TeV gamma-ray emission, both from point sources and diffuse nature. The covered includes 15 known pulsars, 6 supernova remnants (SNR) one unidentified EGRET source. No evidence emission detected; upper limits are typically below 0.1 Crab units flux above 1 TeV. For plane, an limit ph cm-2 s-1 sr-1 MeV-1 derived under assumption that spatial distribution measured by instrument...
OSIRIS is a near infrared diffraction limited imaging field spectrograph under development for the Keck observatory adaptive optics system and scheduled commissioning in fall 2004. Based upon lenslet pupil imaging, grating, 2Kx2K Hawaii2 HgCdTe array, highly efficient instrument at forefront of today's technology. will deliver per readout up to 4096 spectra complex interleaved format, requiring new challenges be met regarding user interaction data reduction. A reduction software package...
We present diffraction-limited spectroscopic observations of an infrared flare associated with the radio source Sgr A*. These are first results obtained OSIRIS, new facility imaging spectrograph for Keck Observatory operated laser guide star (LGS) adaptive optics (AO) system. After subtracting spectrum precursor emission at location A*, we find that has a spectral index [F(ν) ∝ να] α = -2.6 ± 0.9. If do not subtract light, then our is consistent earlier by Ghez et al. All published so far...
We present near infrared ISAAC VLT observations of nine nearby (0.01 ≤ z 0.06) Active Galactic Nuclei selected from the Hamburg/ESO Survey and Véron-Cetty & Véron catalog. Hydrogen recombination lines Paα Brγ are observed in seven sources which five show a broad component. In three sources, extended 1-0S(1) rotational-vibrational molecular hydrogen emission is detected. Stellar CO absorption seen four sources. one these objects, an upper limit central mass can be determined stellar velocity...
We present first results of an exploratory study to use integral field spectroscopy observe extrasolar planets. focus on transiting 'Hot Jupiters' and emphasize the importance observing strategy exact timing. demonstrate how compares with other spectroscopic techniques currently applied. have tested our concept a time series observation HD209458b obtained SINFONI at VLT during superior conjunction.
Aims.We present first results of near-infrared (NIR) J and ESO-SINFONI integral field spectroscopy the composite starburst/Seyfert 1.8 galaxy Mrk 609. The data were taken during science verification period SINFONI. We aim to investigate morphology excitation conditions within central 2 kpc. Additional Nobeyama 45 m CO(1-0) are presented, which we used estimate molecular gas mass. source was selected from a sample SDSS/ROSAT-based, X-ray bright AGN with redshifts that suitable for adaptive...
Abstract SOFIA is an airborne observatory for far-infrared astronomy. Although flies at altitudes of ∼41,000 feet, any observations from within the Earth’s atmosphere are nevertheless hampered by water vapor absorbing astronomical signal. The atmospheric parameter governing absorption total upward precipitable vapor, PWV. In this paper we investigated if data provided European Centre Medium-Range Weather Forecasts, ECMWF, can be used to determine spatially and time-resolved PWV allow a more...
Abstract Transiting exoplanets provide a unique opportunity for follow up exploration through phase-differential observation of their emission and transmission spectra. From such spectra immediate clues about the atmospheric composition planets chemistry can be drawn. Such information is imminent importance theory formation in general as well particular evolution. Ground-based spectroscopy exoplanet transits needful extension results already obtained space-based observations. We present an...