2008A&A...482..237K

We report the discovery of three faint, super-soft X-ray sources in LMC fields observed with XMM-Newton. We analyse the three new sources together with RX J0537.7-7034 and RX J0507.1-6743, both known since ROSAT. We identify XMMU J050803.1-684017 with the LMC planetary nebula LHA 120-N 102=LMC SMP 29. The EPIC-pn spectrum of XMMU J050803.1-684017 can be fitted with a blackbody spectrum with an effective temperature of ~(26-51)eV and a bolometric luminosity of (0.1-30)x10³⁶erg/s, depending on the assumed absorption. The source is consistent with the nucleus of a planetary nebula. The EPIC-pn spectrum of XMMU J052530.5-671501 is characterized by a blackbody temperature of ~(38-120)eV, a best-fit bolometric luminosity of ∼3x10³⁷erg/s and absorbing LMC column of ∼8⁺²_–8x10²¹cm^–2. This most likely highly-absorbed super-soft source resembles the LMC super-soft source CAL 87. The EPIC-pn spectrum of XMMU J052215.0-701658 yields a blackbody temperature of ~(24-83)eV, but there are only about 40 source counts and the spectral parameters of the source are not well constrained. We observe RX J0537.7-7034 with EPIC-pn to be about a factor of 15 fainter compared to the ROSAT observation 11 years earlier. RX J0507.1-6743 is observed as an absorbed super-soft source by XMM-Newton and the improved X-ray position coincides with a MACHO star which is consistent with a symbiotic star.