Simultaneous Multiwavelength Flare Observations of EV Lacertae

November 2021 • 2021ApJ...922...31P

Authors • Paudel, Rishi R. • Barclay, Thomas • Schlieder, Joshua E. • Quintana, Elisa V. • Gilbert, Emily A. • Vega, Laura D. • Youngblood, Allison • Silverstein, Michele • Osten, Rachel A. • Tucker, Michael A. • Huber, Daniel • Do, Aaron • Hamaguchi, Kenji • Mullan, D. J. • Gizis, John E. • Monsue, Teresa A. • Colón, Knicole D. • Boyd, Patricia T. • Davenport, James R. A. • Walkowicz, Lucianne

Abstract • We present the first results of our ongoing project conducting simultaneous multiwavelength observations of flares on nearby active M dwarfs. We acquired data of the nearby dM3.5e star EV Lac using five different observatories: NASA's Transiting Exoplanet Survey Satellite (TESS), NASA's Neil Gehrels Swift Observatory (Swift), NASA's Neutron Interior Composition Explorer (NICER), the University of Hawaii 2.2-meter telescope (UH88), and the Las Cumbres Observatory Global Telescope (LCOGT) Network. During the ~25 days of TESS observations, we acquired three simultaneous UV/X-ray observations using Swift that total ~18 ks, 21 simultaneous epochs totaling ~98 ks of X-ray data using NICER, one observation (~3 hr) with UH88, and one observation (~3 hr) with LCOGT. We identified 56 flares in the TESS light curve with estimated energies in the range log E_T (erg) = (30.5-33.2), nine flares in the Swift UVM2 light curve with estimated energies in the range log E_UV (erg) = (29.3-31.1), 14 flares in the NICER light curve with estimated minimum energies in the range log E_N (erg) = (30.5-32.3), and 1 flare in the LCOGT light curve with log E_L (erg) = 31.6. We find that the flare frequency distributions (FFDs) of TESS and NICER flares have comparable slopes, β_T = -0.67 ± 0.09 and β_N = - 0.65 ± 0.19, and the FFD of UVOT flares has a shallower slope (β_U = -0.38 ± 0.13). Furthermore, we do not find conclusive evidence for either the first ionization potential (FIP) or the inverse FIP effect during coronal flares on EV Lac.

Links

• SIMBAD https://simbad.u-strasbg.fr/simbad/sim-ref?querymethod=bib&simbo=on&submit=submit+bibcode&bibcode=2021ApJ...922...31P
• PDF https://iopscience.iop.org/article/10.3847/1538-4357/ac1946/pdf
• PREPRINT http://arxiv.org/abs/2108.04753
• DATA http://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/biblink.pl?code=2021ApJ...922...31P
• DATA https://irsa.ipac.caltech.edu/bibdata/2021/P/2021ApJ...922...31P.html
• ELECTR https://doi.org/10.3847/1538-4357/ac1946