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We report new detections of the two transient ultraluminous X-ray sources(ULXs) in NGC 5128 from an ongoing series of Chandra observations. Both sourceshave previously been observed Lx (2-3)E39 erg/s, at the lower end of the ULXluminosity range. The new observations allow us to study these sources in theluminosity regime frequented by the Galactic black hole X-ray binaries (BHXBs). We present the recent lightcurves of both ULXs. 1RXH J132519.8-430312(ULX1) was observed at Lx ~ 1E38 erg/s, while CXOU J132518.2-430304 (ULX2)declined to Lx ~ 2E37 erg/s and then lingered at this luminosity for hundredsof days. We show that a reasonable upper limit for both duty cycles is 0.2,with a lower limit of 0.12 for ULX2. This duty cycle is larger than anticipatedfor transient ULXs in old stellar populations. By fitting simple spectralmodels in an observation with ~50 counts we recover properties consistent withGalactic BH XBs, but inconclusive as to the spectral state. We utilise quantileanalyses to demonstrate that the spectra are generally soft, and that in oneobservation the spectrum of ULX2 is inconsistent with a canonical hard state at>95% confidence. This is contrary to what would be expected of an accretingIMBH primary, which we would expect to be in the hard state at theseluminosities. We discuss the paucity of transient ULXs discovered in early-typegalaxies and excogitate explanations. We suggest that the number of transientULXs scales with the giant and sub-giant populations, rather than the totalnumber of XBs.

The fading of two transient ULXs to below the stellar mass Eddington limit