Search Publications
Detecting gravitationally lensed Population III galaxies with the Hubble Space Telescope and the James Webb Space Telescope
Broadhurst, Tom; Schaerer, Daniel; Östlin, Göran +6 more
Small galaxies consisting entirely of Population III (pop III) stars may form at high redshifts, and could constitute one of the best probes of such stars. Here, we explore the prospects of detecting gravitationally lensed pop III galaxies behind the galaxy cluster J0717.5+3745 (J0717) with both the Hubble Space Telescope (HST) and the upcoming Ja…
Suzaku Observations of the Hydra A Cluster out to the Virial Radius
Sato, Kosuke; Fukazawa, Yasushi; Nakazawa, Kazuhiro +12 more
We report on Suzaku observations of the northern half of the Hydra A cluster out to ∼ 1.4 Mpc, reaching the virial radius. There are the first Suzaku observations of a medium-size (kT ∼ 3 keV) cluster out to the virial radius. Two observations were conducted, north-west and north-east offsets, which continue in a filament direction and a void dire…
A 30 AU Radius CO Gas Hole in the Disk around the Herbig Ae Star Oph IRS 48
van Dishoeck, E. F.; Pontoppidan, K. M.; Herczeg, G. J. +1 more
The physical processes leading to the disappearance of disks around young stars are not well understood. A subclass of transitional disks, the so-called cold disks with large inner dust holes, provides a crucial laboratory for studying disk dissipation processes. IRS 48 has a 30 AU radius hole previously measured from dust continuum imaging at 18.…
On the metallicity dependence of crystalline silicates in oxygen-rich asymptotic giant branch stars and red supergiants
Zijlstra, A. A.; Boyer, M. L.; Gielen, C. +10 more
We investigate the occurrence of crystalline silicates in oxygen-rich evolved stars across a range of metallicities and mass-loss rates. It has been suggested that the crystalline silicate feature strength increases with increasing mass-loss rate, implying a correlation between lattice structure and wind density. To test this, we analyse Spitzer I…
Interpretation of combined infrared, submillimeter, and millimeter thermal flux data obtained during the Rosetta fly-by of Asteroid (21) Lutetia
Capaccioni, F.; Lee, S.; Hofstadter, M. +9 more
The European Space Agency’s Rosetta spacecraft is the first Solar System mission to include instrumentation capable of measuring planetary thermal fluxes at both near-IR (VIRTIS) and submillimeter-millimeter (smm-mm, MIRO) wavelengths. Its primary mission is a 1 year reconnaissance of Comet 67P/Churyumov-Gerasimenko beginning in 2014. During a 201…
The Coronal Source of Extreme-ultraviolet Line Profile Asymmetries in Solar Active Region Outflows
Warren, Harry P.; Brooks, David H.
High-resolution spectra from the Hinode EUV Imaging Spectrometer have revealed that coronal spectral line profiles are sometimes asymmetric, with a faint enhancement in the blue wing on the order of 100 km s-1. These asymmetries could be important since they may be subtle yet diagnostically useful signatures of coronal heating or solar …
A broad iron line in LMC X-1
Steiner, James F.; Reis, Rubens C.; Fabian, Andrew C. +6 more
We present results from a deep Suzaku observation of the black hole in LMC X-1, supplemented by coincident monitoring with the Rossi X-ray Timing Explorer (RXTE). We identify broad relativistic reflection features in a soft disc-dominated spectrum. A strong and variable power-law component of emission is present which we use to demonstrate that en…
An extension of the DUSTY radiative transfer code and an application to OH 26.5 and TT Cygni
Groenewegen, M. A. T.
For the best-studied nearby Galactic asymptotic giant branch (AGB) stars a wealth of observational data is typically available in the form of photometry, often extending into the sub-mm, spectra covering a wide wavelength range, and often also visibility curves. Almost 100 AGB stars and red super giants have been imaged as part of the MESS Hersche…
The nucleus of Comet 67P/Churyumov-Gerasimenko. A new shape model and thermophysical analysis
Lowry, S.; Snodgrass, C.; Green, S. F. +5 more
Context. Comet 67P/Churyumov-Gerasimenko is the target of the European Space Agency Rosetta spacecraft rendez-vous mission. Detailed physical characteristation of the comet before arrival is important for mission planning as well as providing a test bed for ground-based observing and data-analysis methods.
Aims: To conduct a long-term observa…
Vertical structure of the Venus cloud top from the VeRa and VIRTIS observations onboard Venus Express
Pätzold, M.; Drossart, P.; Piccioni, G. +6 more
We investigate the Venus cloud top structure by joint analysis of the data from Visual and Thermal Infrared Imaging Spectrometer (VIRTIS) and the atmospheric temperature sounding by the Radio Science experiment (VeRa) onboard Venus Express. The cloud top altitude and aerosol scale height are derived by fitting VIRTIS spectra at 4-5 µm with t…