A 78 DAY X-RAY PERIOD DETECTED FROM NGC 5907 ULX1 BY SWIFT
A 78 DAY X-RAY PERIOD DETECTED FROM NGC 5907 ULX1 BY SWIFT
ABSTRACT We report the detection of a 78.1 ± 0.5 day period in the X-ray light curve of the extreme ultraluminous X-ray source NGC 5907 ULX1 ( <?CDATA ${L}_{{\rm{X,peak}}}\sim 5\times {10}^{40}$?> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi>L</mml:mi> </mml:mrow> <mml:mrow> <mml:mi mathvariant="normal">X,peak</mml:mi> </mml:mrow> </mml:msub> <mml:mo>∼</mml:mo> <mml:mn>5</mml:mn> <mml:mo>×</mml:mo> <mml:msup> <mml:mrow> <mml:mn>10</mml:mn> </mml:mrow> …