Search Publications
Statistical Study of Chromospheric Anemone Jets Observed with Hinode/SOT
Shibata, K.; Kawate, T.; Nakamura, T. +2 more
The Solar Optical Telescope on board Hinode has revealed numerous tiny jets in all regions of the chromosphere outside of sunspots. A typical chromospheric anemone jet has a cusp-shaped structure and bright footpoint, similar to the shape of an X-ray anemone jet observed previously with the Soft X-ray Telescope on board Yohkoh. The similarity in t…
Observational Constraints on Submillimeter Dust Opacity
Bieging, John H.; Wilner, David J.; Shirley, Yancy L. +4 more
Infrared extinction maps and submillimeter dust continuum maps are powerful probes of the density structure in the envelope of star-forming cores. We make a direct comparison between infrared and submillimeter dust continuum observations of the low-mass Class 0 core, B335, to constrain the ratio of submillimeter to infrared opacity (κsmm
A Submillimeter Mapping Survey of Herbig AeBe Stars
Sandell, Göran; Weintraub, David A.; Hamidouche, Murad
We have acquired submillimeter observations of 33 fields containing 37 Herbig Ae/Be (HAEBE) stars or potential HAEBE stars, including SCUBA maps of all but two of these stars. Nine target stars show extended dust emission. The other 18 are unresolved, suggesting that the dust envelopes or disks around these stars are less than a few arcseconds in …
The Edge of the Milky Way Stellar Disk Revealed Using Clump Giant Stars as Distance Indicators
Minniti, D.; Saito, R. K.; Alonso-García, J. +2 more
We use the clump giants of the disk as standard candles calibrated from Hipparcos parallaxes in order to map their distribution with two new near-infrared surveys of the Galactic plane: UKIDSS-GPS and VISTA Variables in the Vía Láctea (VVV). We explore different selection cuts of clump giants. We conclude that there is an edge of the stellar disk …
Expanded Very Large Array Observations of a Proto-cluster of Molecular Gas-rich Galaxies at z = 4.05
Daddi, E.; Walter, F.; Dannerbauer, H. +4 more
We present observations of the molecular gas in the GN20 proto-cluster of galaxies at z = 4.05 using the Expanded Very Large Array (EVLA). This group of galaxies is the ideal laboratory for studying the formation of massive galaxies via luminous, gas-rich starbursts within 1.6 Gyr of the big bang. We detect three galaxies in the proto-cluster in C…
Transverse Oscillations of Loops with Coronal Rain Observed by Hinode/Solar Optical Telescope
Verwichte, E.; Antolin, P.
The condensations composing coronal rain, falling down along loop-like structures observed in cool chromospheric lines such as Hα and Ca II H, have long been a spectacular phenomenon of the solar corona. However, considered a peculiar sporadic phenomenon, it has not received much attention. This picture is rapidly changing due to recent high-resol…
A Multiwavelength Study on the High-energy Behavior of the Fermi/LAT Pulsars
De Luca, Andrea; Marelli, Martino; Caraveo, Patrizia A.
Using archival as well as freshly acquired data, we assess the X-ray behavior of the Fermi/Large Area Telescope γ-ray pulsars listed in the First Fermi source catalog. After revisiting the relationships between the pulsars' rotational energy losses and their X-ray and γ-ray luminosities, we focus on the distance-independent γ-to-X-ray flux ratios.…
Constraining the Minimum Mass of High-redshift Galaxies and their Contribution to the Ionization State of the Intergalactic Medium
Muñoz, J. A.; Loeb, A.
We model the latest HST WFPC3/IR observations of gsim100 galaxies at redshifts z = 7-8 in terms of a hierarchical galaxy formation model with starburst activity. Our model provides a distribution of UV luminosities per dark matter halo of a given mass and a natural explanation for the fraction of halos hosting galaxies. The observed luminosity fun…
Hα and 4000 Å Break Measurements for ~3500 K-selected Galaxies at 0.5 < z < 2.0
van Dokkum, Pieter G.; Franx, Marijn; Labbé, Ivo +3 more
We measure spectral features of ~3500 K-selected galaxies at 0.5 < z < 2.0 from high-quality medium-band photometry using a new technique. First, we divide the galaxy sample in 32 subsamples based on the similarities between the full spectral energy distributions (SEDs) of the galaxies. For each of these 32 galaxy types we construct a compos…
Photometric and Spectroscopic Evolution of the IIP SN 2007it to Day 944
Welch, D. L.; Gallagher, J. S.; Barlow, M. J. +9 more
SN 2007it is a bright, Type IIP supernova which shows indications of both pre-existing and newly formed dust. The visible photometry shows a bright late-time luminosity, powered by the 0.09 M sun of 56Ni present in the ejecta. There is also a sudden drop in optical brightness after day 339, and a corresponding brightening in …