Related papers: Evershed flow observed in neutral and singly ioniz…

We have examined radial velocities and fluxes of ultraviolet emission lines at different epochs, deduced from archival IUE and GRHS/HST spectra. The line fluxes give electron densities and were in addition used to calculate emission…

The velocities and equivalent widths (EWs) of a set of absorption features are measured for a sample of 28 well-observed Type Ia supernovae (SN Ia) covering a wide range of properties. The values of these quantities at maximum are obtained…

We investigated the horizontal and the vertical component of the Evershed flow (EF). To this end, we computed average Stokes V profiles for various velocity classes in penumbrae at different heliocentric angles. Our results show that for…

We present the first detection of neutral atomic oxygen (3P_1-3P_2 fine structure line at ~63um) toward the Horsehead photodissociation region (PDR). The cloud has been mapped with the Spitzer Space Telescope at far-IR (FIR) wavelengths…

In this work we analyse late-time (t > 100 d) optical spectra of low-redshift (z < 0.1) Type Ia supernovae (SNe Ia) which come mostly from the Berkeley Supernova Ia Program dataset. We also present spectra of SN 2011by for the first time.…

The issue of the difference between optical and UV properties of radio-quiet and radio-loud (relativistically "jetted") active galactic nuclei (AGN) is a long standing one, related to the fundamental question of why a minority of powerful…

The moat flow, a radial outflow surrounding fully fledged sunspots, is a well characterised phenomenon. Nevertheless, its origin and especially its relation to the penumbra is still a controversial topic. We investigate the evolution of the…

We present multiple spectropolarimetric observations of the nearby Type Ia supernova (SN) 2011fe in M101, obtained before, during, and after the time of maximum apparent visual brightness. The excellent time coverage of our…

We investigate the evolution of the horizontal flow field around sunspots during their decay by analysing its extension and horizontal velocity around eight spots using SDO/HMI Doppler maps. By assuming a radially symmetrical flow field,…

Doppler shifts of the Fe I spectral line at lambda5250 Angstroms from the full solar disk obtained over the period 1986 to 2009 are analyzed to determine the circulation velocity of the solar surface along meridional planes. Simultaneous…

We present a reanalysis of the HeII Lyman alpha absorption towards the quasars HS1700+6416 and HE2347-4342 using new high S/N, optical observations. An alternative analysis method is applied, which fits the high quality, optical HI data…

Sunspots are crucial for exploring how magnetic fields and plasma flows interact in the solar atmosphere, spanning from the stable photosphere to the shock-dominated chromosphere. To determine the thermal, magnetic, and kinematic properties…

We report on a study of the 2300-2600\AA FeII/FeII* multiplets in the rest-UV spectra of star-forming galaxies at 1.0<z<2.6 as probes of galactic-scale outflows. We extracted a mass-limited sample of 97 galaxies at z~1.0-2.6 from ultra-deep…

The aim of this work is to make available unpublished non-Fe+ emission line fluxes from optical spectra of the symbiotic nova RR Tel which were taken in 2000, and to compare them with fluxes of the same lines from spectra taken in 1996.…

We present FUSE observations of the HeII Lyman alpha forest in the redshift range 2.3 < z < 2.7 towards HS1700+6416. Between October 2002 and February 2003, the brightness of the QSO increased by a factor 2. Therefore, with an exposure time…

We gathered more than 1130 high-resolution optical spectra for more than 250 Galactic classical Cepheids. The spectra were collected with different optical spectrographs: UVES at VLT, HARPS at 3.6m, FEROS at 2.2m MPG/ESO, and STELLA. To…

The predicted emission spectrum of NII is compared with observations of permitted lines in the Orion nebula. Conventional nebular models show that the intensities of the more intense lines can be explained by fluorescence of starlight…

We present the first simultaneous infrared (IR) and visible spectro-polarimetric observations of a solar internetwork region. The Fe I lines at 6301.6 A, 6302.5 A, 15648 A, and 15652 A were observed, with a lag of only 1 min, using highly…

Bright EUV sunspot plumes have been observed in eight out of eleven different sunspot regions with the Coronal Diagnostic Spectrometer -- CDS on SOHO. From wavelength shifts we derive the line-of-sight velocity, relative to the average…

We test the utility of the OII 83.4 nm emission feature as a measure of ionospheric parameters. Observed with the Remote Atmospheric and Ionospheric Detection System (RAIDS) Extreme Ultraviolet Spectrograph on the International Space…