S.A. Drake, E. Behar, J.G. Doyle, M. Güdel, K. Hamaguchi, A.F. Kowalski, T. Maccarone, R.A. Osten, U. Peretz, S.J. Wolk

Stellar Flares Observed by LOFT: Implications for the Physics of Coronae and for the "Space Weather" Environment of Extrasolar Planets

Figure 5: The cumulative flare frequency (in s^òÈÒ1) versus U-band flare energy (in ergs) for G and M-type dwarfs. M dwarf data compiled from Moffett (1974), Doyle & Mathioudakis (1990), Dal & Evren (2011), Hilton (2011), and Hawley et al. (2014). Solar data compiled from Shibayama (2013) and Kretzschmar (2011). G dwarf data from Shibayama et al. (2013). See Ramsay & Doyle (2015) for more details.

Preamble

The Large Observatory for X-ray Timing, LOFT, is specifically designed to perform fast X-ray timing and spectroscopy (Feroci et al. 2014). LOFT focuses on two fundamental questions from ESAòÀÙs Cosmic Vision Theme: what is the equation of state of ultra-dense matter in neutron stars and does matter orbiting close to the event horizon follow the predictions of general relativity? These goals are elaborated in the mission yellow book (sci.esa.int/loft/53447-loft-yellow-book/.)

LOFTòÀÙs primary instrument is the Large Area Detector (LAD), a 8.5m² instrument operating in the 2òÀÓ30 keV energy range, which holds the capability to revolutionise studies of relatively bright X-ray sources down to millisecond time scales. The mission also features a Wide Field Monitor (WFM), observing more than one third of the X-ray sky at any time (2òÀÓ50 keV) and providing for each object detected in its field of view data with good timing and spectral resolution. Additionally, the mission is equipped with an on-board alert system for the detection and rapid broadcasting to the ground of bright X-ray impulsive events (e.g., Gamma-ray Bursts).

LOFT has been studied as a candidate ESA M3 mission during an extensive assessment phase. The high level of readiness and maturity of the mission, as well as the solid assessment of its unique science case, make LOFT a competitive mission with a compelling science case. For this reason, its development has been continued, aiming at new launch opportunities.

The large area and large field of view of LOFTòÀÙs instruments make the mission capable of providing science data not only for its core science case, but also allow it to exploit many other open questions of modern astronomy. This paper is part of a series of White Papers that illustrate these additional capabilities of LOFTòÀÙs "Observatory Science".

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Last Revised: 2015 January 13th