Search Publications

Spectroscopic Observations of an Evolving Flare Ribbon Substructure Suggesting Origin in Current Sheet Waves

Qiu, J.; Longcope, D. W.; Brannon, S. R.

We present imaging and spectroscopic observations from the Interface Region Imaging Spectrograph of the evolution of the flare ribbon in the SOL2014-04-18T13:03 M-class flare event, at high spatial resolution and time cadence. These observations reveal small-scale substructure within the ribbon, which manifests as coherent quasi-periodic oscillati…

Bipolar H II regions - Morphology and star formation in their vicinity. I. G319.88+00.79 and G010.32-00.15

Zavagno, A.; Samal, M. R.; Molinari, S. +9 more

Aims: Our goal is to identify bipolar H ii regions and to understand their morphology, their evolution, and the role they play in the formation of new generations of stars.
Methods: We use the Spitzer-GLIMPSE, -MIPSGAL, and Herschel-Hi-GAL surveys to identify bipolar H ii regions, looking for (ionized) lobes extending perpendicular to de…

Gamma-rays from Type Ia Supernova SN2014J

Sunyaev, R.; Churazov, E.; Bikmaev, I. +8 more

The whole set of INTEGRAL observations of Type Ia supernova SN 2014J, covering the period 19-162 days after the explosion, has been analyzed. For spectral fitting the data are split into early and late periods covering days 19-35 and 50-162, respectively, optimized for ⁵⁶Ni and ⁵⁶Co lines. As expected for the early period, mu…

Small-scale and Global Dynamos and the Area and Flux Distributions of Active Regions, Sunspot Groups, and Sunspots: A Multi-database Study

DeLuca, Edward E.; Pevtsov, Alexei A.; Longcope, Dana W. +12 more

In this work, we take advantage of 11 different sunspot group, sunspot, and active region databases to characterize the area and flux distributions of photospheric magnetic structures. We find that, when taken separately, different databases are better fitted by different distributions (as has been reported previously in the literature). However, …

Star formation in z > 1 3CR host galaxies as seen by Herschel

Clements, D. L.; Meisenheimer, K.; Siebenmorgen, R. +15 more

We present Herschel (PACS and SPIRE) far-infrared (FIR) photometry of a complete sample of z> 1 3CR sources, from the Herschel guaranteed time project The Herschel Legacy of distant radio-loud AGN. Combining these with existing Spitzer photometric data, we perform an infrared (IR) spectral energy distribution (SED) analysis of these landmark ob…

Probing the diffuse baryon distribution with the lensing-tSZ cross-correlation

Van Waerbeke, Ludovic; Hinshaw, Gary; Scott, Douglas +3 more

Approximately half of the Universe's baryons are in a form that has been hard to detect directly. However, the missing component can be traced through the cross-correlation of the thermal Sunyaev-Zeldovich (tSZ) effect with weak gravitational lensing. We build a model for this correlation and use it to constrain the extended baryon component, empl…

NOMAD spectrometer on the ExoMars trace gas orbiter mission: part 1—design, manufacturing and testing of the infrared channels

Vandaele, Ann Carine; Neefs, Eddy; Daerden, Frank +46 more

Discovery of Molecular Gas around HD 131835 in an APEX Molecular Line Survey of Bright Debris Disks

Pascucci, I.; Ábrahám, P.; Kóspál, Á. +11 more

Debris disks are considered to be gas-poor, but recent observations revealed molecular or atomic gas in several 10-40 Myr old systems. We used the APEX and IRAM 30 m radio telescopes to search for CO gas in 20 bright debris disks. In one case, around the 16 Myr old A-type star HD 131835, we discovered a new gas-bearing debris disk, where the CO 3-…

Red Supergiants as Cosmic Abundance Probes: The Sculptor Galaxy NGC 300

Bender, Ralf; Bonanos, Alceste Z.; Bresolin, Fabio +9 more

We present a quantitative spectroscopic study of 27 red supergiants (RSGs) in the Sculptor Galaxy NGC 300. J-band spectra were obtained using KMOS on the Very Large Telescope and studied with state of the art synthetic spectra including NLTE corrections for the strongest diagnostic lines. We report a central metallicity of [Z] = -0.03 ± 0.05 with …

Persistent aeolian activity at Endeavour crater, Meridiani Planum, Mars; new observations from orbit and the surface

Johnson, Jeffrey R.; Chojnacki, Matthew; Moersch, Jeffrey E. +3 more

Aeolian-driven bedform activity is now known to occur in many regions of Mars, based on surface and orbital observation of contemporary martian ripple and dune mobility events. Many of these sites have only been monitored with sufficient resolution data for the last few Mars years, when the High Resolution Imaging Science Experiment (HiRISE) began…