Solar and Stellar Flares and their Effects on Planets Proceedings IAU Symposium No. 320, 2015 A.G. Kosovichev, S.L. Hawley & P. Heinzel, eds. c  International Astronomical Union 2016 doi:10.1017/S174392131600034X Spectroscopic UV observations of M 1.0 class solar flare from IRIS satellite Viacheslav M Sadykov 1 , Alexander G Kosovichev 1,2 , Ivan N Sharykin 3 and Santiago Vargas Dominguez 4 1 New Jersey Institute of Technology, Newark, NJ 07102, USA email: vsadykov@njit.edu 2 NASA Ames Research Center, Moffet Field, CA 94035, USA 3 Space Research Institute (IKI), Moscow 117997, Russia 4 Observ. Astron. Univ. Nacional de Colombia, Bogot´ a 111321, Colombia Abstract. This work presents an analysis of UV spectroscopic observations from the IRIS satellite of an M1.0 class flare occurred on 12 June 2014 in active region NOAA 12087. Our analysis of the IRIS spectra and Slit-Jaw images revealed presence of a strongly redshifted chromospheric jet before the flare. We also found strong emission of the chromospheric lines, and studied the C II 1334.5 ˚ A line emission distribution in details. A blueshift of the Fe XXI line across the flaring region corresponds to evaporation flows of the hot chromospheric plasma with a speed of 50 km/s. Although the enhancement of the C II line integrated redshift correlates with the flare X-ray emission, we classify the evaporation as of a “gentle” type because of its long time scale and subsonic velocities. Analysis of X-ray data from the RHESSI satellite showed that both, an injection of accelerated particles and a heat flux from the energy release site can explain the energetics of the observed event. Keywords. Sun: activity, flares, magnetic fields, atmosphere, UV radiation 1. Introduction Spectroscopic observations represent a powerful instrument to study solar flares (Mil- ligan 2015). For the processes associated with plasma flows (like jets and chromospheric evaporations (Brosius & Phillips 2004; Milligan et al. 2006; Doshchek et al. 2013)) the spectroscopic observations are essentially important. The recent NASA’s Interface Re- gion Imaging Spectrograph (IRIS) mission (De Pontieu et al. 2014) allows us to observe several strong UV lines forming in the upper chromosphere and transition region (e.g. Mg II h&k, Si IV and C II lines) and in the high-temperature coronal plasma (Fe XXI line). High spectral (26-53 m ˚ A), spatial (0.33 arcsec), and temporal (≈2 sec) resolutions make this telescope a unique instrument for the spectroscopic observations. The M1.0 class flare of 12 June, 2014 was of our particular interest because of the simultaneous observations by the IRIS satellite and New Solar Telescope (NST, Goode et al. 2010). For the NST observational details, we refer to Sadykov et al. (2014) and Kumar et al. (2015). We have also used data from the GOES (Bornmann et al. 1996) and RHESSI (Lin et al. 2002), and from Solar Dynamic Observatory (SDO) Helioseismic and Magnetic Imager (HMI) (Scherrer et al. 2012) and Atmospheric Imaging Assembly (AIA) (Lemen et al. 2012) instruments. 64 https://www.cambridge.org/core/terms. https://doi.org/10.1017/S174392131600034X Downloaded from https://www.cambridge.org/core. IP address: 54.70.40.11, on 18 Jun 2019 at 16:12:56, subject to the Cambridge Core terms of use, available at