Search Publications
The Coupled Physical Structure of Gas and Dust in the IM Lup Protoplanetary Disk
Wilner, David J.; Cleeves, L. Ilsedore; Andrews, Sean M. +4 more
The spatial distribution of gas and solids in protoplanetary disks determines the composition and formation efficiency of planetary systems. A number of disks show starkly different distributions for the gas and small grains compared to millimeter-centimeter-sized dust. We present new Atacama Large Millimeter/Submillimeter Array observations of th…
The faint radio sky: radio astronomy becomes mainstream
Padovani, Paolo
Radio astronomy has changed. For years it studied relatively rare sources, which emit mostly non-thermal radiation across the entire electromagnetic spectrum, I.e. radio quasars and radio galaxies. Now, it is reaching such faint flux densities that it detects mainly star-forming galaxies and the more common radio-quiet active galactic nuclei. Thes…
Beyond 31 mag arcsec-2: The Frontier of Low Surface Brightness Imaging with the Largest Optical Telescopes
Trujillo, Ignacio; Fliri, Jüergen
The detection of structures in the sky with optical surface brightnesses fainter than 30 mag arcsec-2 (3σ in 10 × 10 arcsec boxes; r-band) has remained elusive in current photometric deep surveys. Here we show how present-day telescopes of 10 m class can provide broadband imaging 1.5-2 mag deeper than most previous results within a reas…
Aggregate dust particles at comet 67P/Churyumov-Gerasimenko
Jessberger, Elmar K.; Torkar, Klaus; Levasseur-Regourd, Anny-Chantal +9 more
Comets are thought to preserve almost pristine dust particles, thus providing a unique sample of the properties of the early solar nebula. The microscopic properties of this dust played a key part in particle aggregation during the formation of the Solar System. Cometary dust was previously considered to comprise irregular, fluffy agglomerates on …
The Atmospheric Circulation of a Nine-hot-Jupiter Sample: Probing Circulation and Chemistry over a Wide Phase Space
Fortney, Jonathan J.; Sing, David K.; Kataria, Tiffany +4 more
We present results from an atmospheric circulation study of nine hot Jupiters that compose a large transmission spectral survey using the Hubble and Spitzer Space Telescopes. These observations exhibit a range of spectral behavior over optical and infrared wavelengths, suggesting diverse cloud and haze properties in their atmospheres. By utilizing…
Magnetohydrodynamic simulation of interplanetary propagation of multiple coronal mass ejections with internal magnetic flux rope (SUSANOO-CME)
Kataoka, R.; Shiota, D.
Coronal mass ejections (CMEs) are the most important drivers of various types of space weather disturbance. Here we report a newly developed magnetohydrodynamic (MHD) simulation of the solar wind, including a series of multiple CMEs with internal spheromak-type magnetic fields. First, the polarity of the spheromak magnetic field is set as determin…
Cold, clumpy accretion onto an active supermassive black hole
Baum, Stefi A.; O'Dea, Christopher P.; McNamara, Brian R. +22 more
Supermassive black holes in galaxy centres can grow by the accretion of gas, liberating energy that might regulate star formation on galaxy-wide scales. The nature of the gaseous fuel reservoirs that power black hole growth is nevertheless largely unconstrained by observations, and is instead routinely simplified as a smooth, spherical inflow of v…
The effects of high density on the X-ray spectrum reflected from accretion discs around black holes
Steiner, James F.; Fabian, Andrew C.; McClintock, Jeffrey E. +5 more
Current models of the spectrum of X-rays reflected from accretion discs around black holes and other compact objects are commonly calculated assuming that the density of the disc atmosphere is constant within several Thomson depths from the irradiated surface. An important simplifying assumption of these models is that the ionization structure of …
The Bright End of the z ∼ 9 and z ∼ 10 UV Luminosity Functions Using All Five CANDELS Fields*
Trenti, M.; Oesch, P. A.; Fazio, G. G. +14 more
The deep, wide-area (∼800-900 arcmin2) near-infrared/WFC3/IR + Spitzer/IRAC observations over the CANDELS fields have been a remarkable resource for constraining the bright end of high-redshift UV luminosity functions. However, the lack of Hubble Space Telescope (HST) 1.05 µm observations over the CANDELS fields has made it diffic…
PTF12os and iPTF13bvn. Two stripped-envelope supernovae from low-mass progenitors in NGC 5806
Pian, E.; Sollerman, J.; Gal-Yam, A. +19 more
Context. We investigate two stripped-envelope supernovae (SNe) discovered in the nearby galaxy NGC 5806 by the (intermediate) Palomar Transient Factory [(I)PTF]. These SNe, designated PTF12os/SN 2012P and iPTF13bvn, exploded within ~520 days of one another at a similar distance from the host-galaxy center. We classify PTF12os as a Type IIb SN base…