A5026119962- Astro and Planetary Science
- Planetary Science and Exploration
- Space Exploration and Technology
- Geomagnetism and Paleomagnetism Studies
- Astronomy and Astrophysical Research
- Geology and Paleoclimatology Research
- Stellar, planetary, and galactic studies
- Astrophysics and Star Formation Studies
- Solar and Space Plasma Dynamics
- Isotope Analysis in Ecology
- Galaxies: Formation, Evolution, Phenomena
- Gamma-ray bursts and supernovae
- Ionosphere and magnetosphere dynamics
- CCD and CMOS Imaging Sensors
- Astrophysical Phenomena and Observations
- Laser-induced spectroscopy and plasma
- Space Science and Extraterrestrial Life
- Astronomical Observations and Instrumentation
- Infrared Target Detection Methodologies
- Pulsars and Gravitational Waves Research
- Astrophysics and Cosmic Phenomena
- Radio Astronomy Observations and Technology
- Scientific Research and Discoveries
- History and Developments in Astronomy
- Calibration and Measurement Techniques
Deutsches Zentrum für Luft- und Raumfahrt e. V. (DLR)
2023
California Institute of Technology
2011-2022
Herzberg Institute of Astrophysics
2009-2010
Goddard Space Flight Center
2008
Jet Propulsion Laboratory
2008
Goddard Institute for Space Studies
2008
Space Science Institute
2008
Space Telescope Science Institute
1991-1993
The Cosmic Evolution Survey (COSMOS) was initiated with an extensive allocation (590 orbits in Cycles 12-13) using the Hubble Space Telescope (HST) for high resolution imaging. Here we review characteristics of HST imaging Advanced Camera Surveys (ACS) and parallel observations NICMOS WFPC2. A square field (1.8$\sq$\deg) has been imaged single-orbit ACS I-F814W exposures 50% completeness sources 0.5\arcsec diameter at I$_{AB} $ = 26.0 mag. is a key part COSMOS survey, providing very...
We present the final results from a high sampling rate, multi-month, spectrophotometric reverberation mapping campaign undertaken to obtain either new or improved Hβ lag measurements for several relatively low-luminosity active galactic nuclei (AGNs). have reliably measured time delay between variations in continuum and emission line six local Seyfert 1 galaxies. These are used calculate mass of supermassive black hole at center each these AGNs. place our context most current calibration...
We present Hubble Space Telescope WFPC2 images of elephant trunks in the H II region M16. There are three principle results this study. First, morphology and stratified ionization structure interface between dense molecular material interior is well understood terms photoionization a photoevaporative flow. Photoionization models an empirical density profile capture essential features observations, including extremely localized [S II] emission at observed offset peaks lower higher lines. The...
We have discovered a population of bright blue pointlike sources within 5 kpc the nucleus NGC 1275 using HST Planetary Camera observations. The typical object has M_v_ ~ - 12 to 14 (H_0_ = 75 km s^-1^ Mpc^-1^ ); brightest 16. They are all blue, with V R <~ 0.3. color distribution and lack excess Hα emission consistent nearly being continuum sources. Many unresolved even consequently sizes 15 pc. suggest that these young star clusters will evolve look like globular clusters. bluer than any...
We have obtained Hα and Paα emission-line images covering the central 3'–4' of M51 using WFPC2 NICMOS instruments on Hubble Space Telescope to study high-mass stellar population. The 01–02 pixels provide 4.6–9 pc resolution in M51, Hα/Paα line ratios are used obtain extinction estimates. A sample 1373 emission regions is cataloged an automated uniform measurement algorithm. Their sizes typically 10–100 pc. luminosity function for over range LHα = 1036 2 × 1039 ergs s-1. fitted well by a...
A detailed analysis of the data from a high sampling rate, multi-month reverberation mapping campaign, undertaken primarily at MDM Observatory with supporting observations telescopes around world, reveals that Hbeta emission region within broad line regions (BLRs) several nearby AGNs exhibit variety kinematic behaviors. While primary goal this campaign was to obtain either new or improved lag measurements for relatively low luminosity (presented in separate work), we were also able...
Abstract The Juno microwave radiometer measured the thermal emission from Jupiter's atmosphere cloud tops at about 1 bar to as deep a hundred bars of pressure during its first flyby over Jupiter (PJ1). nadir brightness temperatures show that Equatorial Zone is likely be an ideal adiabat, which allows determination ammonia abundance in range ppm. combination Markov chain Monte Carlo method and Tikhonov regularization studied invert global distribution assuming prescribed temperature profile....
V- and I-band HST Planetary Camera images of the great spiral galaxy in Andromeda, M31, show that its inner nucleus consists two components separated by 0.49". The outer isophotes at 1.4" < r 3.0" are elongated, but concentric with M31 bulge. nuclear component lower surface brightness, P2, is also coincident bulge photocenter to ~0,05"; we argue it kinematic center galaxy. brighter component, P1, well resolved corresponds core imaged Stratoscope II. central V-band luminosity density for P1 5...
A survey of dust devils using the Mars Global Surveyor (MGS) Orbiter Camera (MOC) wide‐ and narrow‐angle (WA NA) images has been undertaken. The comprises two parts: (1) sampling nine broad regions from September 1997 to July 2001 (2) a focused seasonal monitoring variability in Amazonis region, an active devil site, March April 2004. For part 1, were identified NA WA images, tracks images. Great spatial occurrence is highlighted, with Planitia being most region examined. Other included...
A global dust storm occurred on Mars between June and October 2001. The began near Hellas just before southern spring equinox (∼ L s = 177°). Local storms, likely forced by a combination of slope‐flow ice cap thermal contrasts, were observed to propagate along the northwestern rim Hellas, apparently triggering storm. Cap‐edge activity for much late winter was similar in 2001 one year earlier; however, very large propagated into basin after 177°. Subsequently, total area roughly double that...
The radiant energy budget and internal heat are fundamental properties of giant planets, but precise determination these remains a challenge. Here, we report measurements Jupiter's based on Cassini multi-instrument observations. Our findings reveal that Bond albedo heat, 0.503 ± 0.012 7.485 0.160 W m-2 respectively, significantly larger than 0.343 0.032 5.444 0.425 Wm-2, the previous best estimates. new results help constrain improve current evolutionary theories models for Jupiter....
Abstract Jupiter’s atmosphere is one of the most turbulent places in solar system. Whereas observations lightning and thunderstorms point to moist convection as a small-scale energy source for large-scale vortices zonal jets, this has never been demonstrated due coarse resolution pre-Juno measurements. The Juno spacecraft discovered that Jovian high latitudes host cluster large cyclones with diameter around 5,000 km, each associated intermediate- (roughly between 500 1,600 km) smaller-scale...
Large eddy simulations of vertical convective vortices and dust devils in the Martian boundary layer are presented, employing a version Mars MM5 mesoscale model, adapted to use periodic conditions run at resolutions 10 100 m. The effects background horizontal wind speed shear on devil development studied four simulations, each extending over daytime portion one day. general vorticity all cases is similar, with roughly equal positive negative extrema. Two were found develop highest case...
Analysis of V and I band HST Planetary Camera images the giant elliptical galaxy M87 show that its central starlight distribution is consistent with black hole M_black hole_ = 2.6 X 10^9^ M_sun_ cusp model proposed for by Young et al, [ApJ, 221,721(1978)]. A combined approach image deconvolution modeling used to investigate into limiting radii ~0.04" (3 pc at 16 Mpc). The structure can be described three components: a power-law profile form μ(r) proportional r^- 1/4^ r < 3", nonthermal...
Until now, evidence for lightning on Saturn has been indirect – through radio emissions and cloud morphology. Here we report the first visible detection of lightning, night side August 17, 2009 at −36.4° ± 0.1° planetocentric latitude 10.6° 0.9° west longitude. No other locations produced detectable by either imaging or radio. The images are consistent with a single flashing once per minute. energy flash is comparable to that Earth Jupiter, ranges up 1.7 × 10 9 Joules. diameter flashes ∼200...