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Soft X-Ray Excess from Shocked Black Hole Accretion

Fukumura, Keigo; Przybylek, Jeff

A certain class of luminous galaxies hosting supermassive black holes (BHs) is known to exhibit an excess of "soft X-rays" in their X-ray spectra. However, its physical identity and origin are yet to be understood. In this work, we systematically study a sample of 9 well-documented narrow-line Seyfert 1 active galactic nuclei by utilizing the arch…

X-Ray and Optical Observations of the Young M Dwarf Dipper Star TIC 234284556

Montet, Benjamin T.; Feinstein, Adina D.; Poppenhaeger, Katja +2 more

We observed TIC 234284556 in X-rays and in the optical with XMM-Newton to study the recurring dip previously seen in TESS observations. The dip did not appear during our observation. We detect X-ray flares and anti-correlated rotational modulation in X-rays and in the optical.