Browsing by Author "Komljenovic, M"

Now showing 1 - 1 of 1
  • Thumbnail Image
    Item
    The extinction and distance of Maffei 1
    (University of Chicago Press, 2003) Fingerhut, RL; McCall, ML; De Robertis, M; Kingsburgh, RL; Komljenovic, M; Lee, H; Buta, RJ; York University - Canada; University of Alabama Tuscaloosa
    We have obtained low- and high-resolution spectra of the core of the highly reddened elliptical galaxy Maffei 1. From these data, we have obtained the first measurement of the Mg-2 index and have measured the velocity dispersion and radial velocity with improved accuracy. To evaluate the extinction, a correlation between the Mg-2 index and effective V-I color has been established for elliptical galaxies. Using a new method for correcting for effective wavelength shifts, the V-I color excess reveals that the optical depth of Galactic dust at 1 mum is 1.69 +/- 0.07. Thus, A(V) = 4.67 +/- 0.19 mag, which is lower by 0.4 mag than previously thought. To establish the distance, the fundamental plane for elliptical galaxies has been constructed in I. The velocity dispersion of Maffei 1, measured to be 186.8 +/- 7.4 km s(-1), in combination with modern wide. field photometry in I, leads to a distance of 2.92 +/- 0.37 Mpc. The D-n-sigma relation, which is independently calibrated, gives 3.08 +/- 0.85 and 3.23 +/- 0.67 Mpc from photometry in B and K', respectively. The weighted mean of the three estimates is 3.01 +/- 0.30 Mpc, which is lower than distances judged with reference to M32 and the bulge of M31 from the brightest stars seen at K'. Since the luminosity of asymptotic giant branch stars at K' is strongly dependent on age, the lower distance suggests that the last epoch of star formation in Maffei 1 occurred farther in the past than in these other systems. The distance and luminosity make Maffei 1 the nearest giant elliptical galaxy. In the absence of extinction, the galaxy would be among the brightest in the sky and would have an apparent size 2/3 that of the full Moon. The radial velocity of Maffei 1 is + 66.4 +/- 5.0 km s(-1), significantly higher than the accepted value of -10 km s(-1). The Hubble distance corresponding to the mean velocity of Maffei 1, Maffei 2, and IC 342 is 3.5 Mpc. Thus, it is unlikely that Maffei 1 has had any influence on Local Group dynamics.