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UV Spectra, Bombs, and the Solar Atmosphere
Judge, Philip G.
A recent analysis of UV data from the Interface Region Imaging Spectrograph (IRIS) reports plasma “bombs” with temperatures near 8 × 104 K within the solar photosphere. This is a curious result, first because most bomb plasma pressures p (the largest reported case exceeds 103 dyn cm-2) fall well below photospheric …
Identification of a Class of Low-mass Asymptotic Giant Branch Stars Struggling to Become Carbon Stars in the Magellanic Clouds
Boyer, Martha L.; Sonneborn, George; van Loon, Jacco Th. +4 more
We have identified a new class of Asymptotic Giant Branch (AGB) stars in the Small and Large Magellanic Clouds (SMC/LMC) using optical to infrared photometry, light curves, and optical spectroscopy. The strong dust production and long-period pulsations of these stars indicate that they are at the very end of their AGB evolution. Period-mass-radius…
Synthesized Spectra of Optically Thin Emission Lines
De Pontieu, B.; Hansteen, V. H.; Olluri, K. +1 more
In recent years realistic 3D numerical models of the solar atmosphere have become available. The models attempt to recreate the solar atmosphere and mimic observations in the best way, in order to make it possible to couple complicated observations with physical properties such as the temperatures, densities, velocities, and magnetic fields. We he…
Internetwork Chromospheric Bright Grains Observed With IRIS and SST
Golub, Leon; Testa, Paola; Martínez-Sykora, Juan +18 more
The Interface Region Imaging Spectrograph (IRIS) reveals small-scale rapid brightenings in the form of bright grains all over coronal holes and the quiet Sun. These bright grains are seen with the IRIS 1330, 1400, and 2796 Å slit-jaw filters. We combine coordinated observations with IRIS and from the ground with the Swedish 1 m Solar Telescope (SS…
Far-infrared Line Spectra of Seyfert Galaxies from the Herschel-PACS Spectrometer
Spinoglio, Luigi; Malkan, Matthew A.; Pereira-Santaella, Miguel +4 more
We observed the far-IR fine-structure lines of 26 Seyfert galaxies with the Herschel-PACS spectrometer. These observations are complemented with Spitzer Infrared Spectrograph and Herschel SPIRE spectroscopy. We used the ionic lines to determine electron densities in the ionized gas and the [C I] lines, observed with SPIRE, to measure the neutral g…
Detections of Trans-Neptunian Ice in Protoplanetary Disks
Manoj, P.; Watson, D. M.; Sargent, B. +6 more
We present Herschel Space Observatory PACS spectra of T Tauri stars, in which we detect amorphous and crystalline water ice features. Using irradiated accretion disk models, we determine the disk structure and ice abundance in each of the systems. Combining a model-independent comparison of the ice feature strength and disk size with a detailed an…
Radio Jet Feedback and Star Formation in Heavily Obscured, Hyperluminous Quasars at Redshifts ∼ 0.5-3. I. ALMA Observations
Stern, D.; Smith, R.; Blain, A. +17 more
We present Atacama Large Millimeter/submillimeter Array (ALMA) 870 µm (345 GHz) data for 49 high-redshift (0.47 < z < 2.85), luminous (11.7\lt {log}({L}{{bol}}/{L}⊙ )\lt 14.2) radio-powerful active galactic nuclei (AGNs), obtained to constrain cool dust emission from starbursts concurrent with highly obscured radi…
Properties of Chromospheric Evaporation and Plasma Dynamics of a Solar Flare from Iris
Kosovichev, Alexander G.; Sadykov, Viacheslav M.; Sharykin, Ivan N. +3 more
The dynamics of hot chromospheric plasma of solar flares is a key to understanding the mechanisms of flare energy release and particle acceleration. A moderate M1.0 class flare of 2014 June 12, (SOL2014-06-12T21:12) was simultaneously observed by NASA's Interface Region Imaging Spectrograph (IRIS) and other spacecraft, and also by the New Solar Te…
Star Formation Activity in CLASH Brightest Cluster Galaxies
Donahue, Megan; Moustakas, John; Connor, Thomas +2 more
The CLASH X-ray selected sample of 20 galaxy clusters contains 10 brightest cluster galaxies (BCGs) that exhibit significant (>5σ) extinction-corrected star formation rates (SFRs). Star formation activity is inferred from photometric estimates of UV and Hα+[N ii] emission in knots and filaments detected in CLASH Hubble Space Telescope ACS and W…
Discovery of a Strongly Phase-variable Spectral Feature in the Isolated Neutron Star RX J0720.4-3125
Tiengo, A.; Rea, N.; Turolla, R. +2 more
We present the discovery of a strongly phase-variable absorption feature in the X-ray spectrum of the nearby, thermally emitting, isolated neutron star RX J0720.4-3125. The absorption line was detected performing detailed phase-resolved spectroscopy in 20 XMM-Newton observations, covering the period 2000 May-2012 September. The feature has an ener…