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We review the accuracy of existing \ion{Fe}{17} X-ray line emission models by comparing them with an extensive analysis of \textit{Chandra} high energy transmission grating (HETG) observations of stellar coronae. We find significant…

Solar and Stellar Astrophysics · Physics 2009-05-06 M. F. Gu

Spectroscopic observations with the EUV Imaging Spectrometer (EIS) on Hinode have revealed large areas of high speed outflows at the periphery of many solar active regions. These outflows are of interest because they may connect to the…

Solar and Stellar Astrophysics · Physics 2015-05-19 Harry P. Warren , Ignacio Ugarte-Urra , Peter R. Young , Guillermo Stenborg

The Fe I 6173 {\AA} line is widely used in the measurements of vector magnetic fields by instruments including the Helioseismic and Magnetic Imager (HMI). We perform non-local thermodynamic equilibrium calculations of this line based on…

Solar and Stellar Astrophysics · Physics 2018-04-10 Jie Hong , M. D. Ding , Ying Li , Mats Carlsson

We report multi-wavelength observations of four solar flares on 2014 July 07. We firstly select these flares according to the soft X-ray (SXR) and extreme ultraviolet (EUV) emissions recorded by the Extreme Ultraviolet Variability…

Solar and Stellar Astrophysics · Physics 2021-05-05 Dong Li , Alexander Warmuth , Lei Lu , Zongjun Ning

We present plasma diagnostics of an EIT wave observed with high cadence in Hinode/EIS sit-and-stare spectroscopy and SDO/AIA imagery obtained during the HOP-180 observing campaign on 2011 February 16. At the propagating EIT wave front, we…

Solar and Stellar Astrophysics · Physics 2015-06-03 A. M. Veronig , P. Gomory , I. W. Kienreich , N. Muhr , B. Vrsnak , M. Temmer , H. P. Warren

After decades of uncertainty about the origin of lithium, recent evidence suggests Galactic novae as its main astrophysical source. In this work, we present possible evidence for the first detection of the $^7$Be line at 478 keV, observed…

High Energy Astrophysical Phenomena · Physics 2025-06-25 L. Izzo , T. Siegert , P. Jean , P. Molaro , P. Bonifacio , M. Della Valle , T. Parsotan

The EUV Imaging Spectrometer (EIS) on the Hinode satellite is capable of measuring emission line center positions for Gaussian line profiles to a fraction of a spectral pixel, resulting in relative solar Doppler-shift measurements with an…

Observations from the 2012 transit of Venus are used to derive empirical formulae for long and short-range scattered light at locations on the solar disk observed by the Hinode Extreme ultraviolet Imaging Spectrometer (EIS) and the Solar…

Solar and Stellar Astrophysics · Physics 2022-10-26 Peter R. Young , Nicholeen M. Viall

The present work illustrates the potential of a new diagnostic technique that allows the measurement of the coronal magnetic field strength in solar active regions utilizing a handful of bright \ion[Fe x] and \ion[Fe xi] lines commonly…

Solar and Stellar Astrophysics · Physics 2020-12-02 E. Landi , R. Hutton , T. Brage , W. Li

The COBE Far InfraRed Absolute Spectrophotometer (FIRAS) observations constitute an unbiased survey over the wavelength range from 100 um to 1 cm over 99% of the sky. Improved calibration of the FIRAS instrument and the inclusion of all of…

Astrophysics · Physics 2007-05-23 D. J. Fixsen , C. L. Bennett , J. C. Mather

The unprecedented sensitivity of current X-ray telescopes allows for the first time to address the issue of the Fe K line complex variability patterns in bright, nearby AGNs. We examine XMM-Newton observations of the brightest sources of…

High Energy Astrophysical Phenomena · Physics 2015-05-13 B. De Marco , K. Iwasawa , M. Cappi , M. Dadina , F. Tombesi , G. Ponti , A. Celotti , G. Miniutti

The 6307A emission line in the spectrum of Eta Car (Martin et al. 2006) is blue-shifted [S III] 6313A emission originating from the outer wind structures of the massive binary system. We realized the identification while analyzing multiple…

Solar and Stellar Astrophysics · Physics 2015-05-14 T. R. Gull

We present deep Keck/MOSFIRE $H$-band spectroscopic observations covering the [CIII],CIII]$\lambda\lambda1907,1909$ doublet for three $z\sim8$ galaxy candidates in the AEGIS field. Along with non-detections in two galaxies, we obtain one of…

In previous studies a very hot plasma component has been diagnosed in solar active regions through the images in three different narrow-band channels of SDO/AIA. This diagnostic from EUV imaging data has also been supported by the matching…

Solar and Stellar Astrophysics · Physics 2015-06-18 A. Petralia , F. Reale , P. Testa , G. Del Zanna

The gravitational redshift measured by Cottam, Paerels and Mendez for the neutron star (NS) in the low-mass X-ray binary EXO 0748-676 depends on the identification of an absorption line during a type I burst as the H$\alpha$ line from…

Astrophysics · Physics 2009-11-07 L. Bildsten , P. Chang , F. Paerels

As noted first by Sunyaev & Churazov (1984), the 3.071 mm hyperfine line from $^{57}Fe^{+23}$ might be observable in astrophysical plasmas. We assess the atomic processes which might contribute to the excitation of this line. We determine…

Astrophysics · Physics 2009-10-30 Noella L. D'Cruz , Craig L. Sarazin , Jacques Dubau

We present spectroscopic observations of FIR fine-structure lines of 26 Seyfert galaxies obtained with the Herschel-PACS spectrometer. These observations are complemented by spectroscopy with Spitzer-IRS and Herschel-SPIRE. The ratios of…

Spectra of the bright symbiotic star AG Draconis (BD+67D922) in the wavelength range 905-1187 A obtained with the Far Ultraviolet Spectroscopic Explorer (FUSE) are presented. The spectra show a number of narrow, nebular emission lines,…

Astrophysics · Physics 2007-05-23 P. R. Young , A. K. Dupree , B. R. Espey , S. J. Kenyon , T. B. Ake

We develop a novel statistical approach to identify emission features or set upper limits in high-resolution spectra in the presence of high background. The method relies on detecting differences from the background using smooth tests and…

Instrumentation and Methods for Astrophysics · Physics 2023-03-10 Xiangyu Zhang , Sara Algeri , Vinay Kashyap , Margarita Karovska

Temporally-resolved electron density measurements of solar flare plasmas are presented using data from the EUV Variability Experiment (EVE) onboard the Solar Dynamics Observatory (SDO). The EVE spectral range contains emission lines formed…

Solar and Stellar Astrophysics · Physics 2015-06-05 Ryan O. Milligan , Michael B. Kennedy , Mihalis Mathioudakis , Francis P. Keenan
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