Erratum: “Follow-Up Hubble Space Telescope/Space Telescope Imaging Spectroscopy of Three Candidate Tidal Disruption Events” (ApJ, 592, 42 [2003])

Abstract

The fluxes of the emission lines in the HST/STIS spectra of NGC 5905 given in Table 3 were incorrect by multiplicative factors of 2.5 from the G430L spectrum, and 0.5 from the G750M spectrum. This error does not affect the diagnostic line ratios from neighboring lines or the principal conclusions of the paper. A corrected version of Table 3 is given here. The only quantitative change in interpretation comes from the revised Balmer decrement in the nucleus of NGC 5905, H /H 1⁄4 2:50 0:34, which indicates that there is no reddening in the line of sight, and is now consistent with the lack of X-ray absorption in the ROSAT flare spectrum. Thus, we no longer make extinction corrections, and the density estimates for the lineemitting gas calculated in x 4.3 are lowered. The corrected H luminosity of 5:1 10 ergs s 1 implies fcnH 330 cm , while the corrected [O iii] luminosity of 3:5 10 ergs s 1 implies ne fc 240 cm . These constraints, in addition to the unchanged [S ii] line ratio, which requires ne 500 cm , are consistent with photoionized clouds of nH 10 and a large covering fraction fc. The soft X-ray luminosity predicted in x 4.3 for the Seyfert nucleus in NGC 5905, using the correlation of soft X-ray luminosity with H , is 9 10 ergs s , now an order of magnitude below the lowest value observed by the ROSAT PSPC (LX 2 10 ergs s ). It is still argued that the latter detection might also be partly associated with its nuclear starburst. The corrected luminosity of H is 10 times less than the peak H luminosity powered by the flare as calculated in x 4.3, while He ii k4686 is still not detected and can be assigned an upper limit of 1:5 10 ergs s . These corrected values are still evidence that the emission lines are not powered by the flare; He ii k4686 would be expected to be even stronger than H for gas ionized by the flare. In x 4.4 we referred to the possibility of ‘‘a gross error in the H /H measurement in the STIS spectrum due primarily to stellar absorption in those lines.’’ Instead, there was a numerical error, not a physical one.