Photometry for the Halo Stars in the Leo Elliptical NGC 3377
نویسندگان
چکیده
We have used the ACS camera on HST to obtain (V, I) photometry for 57,000 red-giant stars in the halo of the Leo elliptical NGC 3377, an intermediateluminosity elliptical. We use this sample of stars to derive the metallicity distribution function (MDF) for its halo field stars, and comment on its chemical evolution history compared with both larger and smaller E galaxies. Our ACS/WFC field spans a radial range extending from 4 to 18 kpc projected distance from the center of NGC 3377 and thus covers a significant portion of this galaxy’s halo. We find that the MDF is broad, reaching a peak at log (Z/Z⊙) ≃ −0.6, but containing virtually no stars more metal-poor than log (Z/Z⊙) = −1.5. It may, in addition, have relatively few stars more metal-rich than log (Z/Z⊙) = −0.3,
منابع مشابه
The Mass Distribution in the Elliptical Galaxy Ngc 3377 : Evidence for a 2 108 - M
This paper is a study of the mass distribution in the central 35 00 ' 1.7 kpc of the E5 galaxy NGC 3377. Stellar rotation velocity and velocity dispersion prooles (seeing = 0. 00 20 { 0. 00 56) and V-band surface photometry (= 0. 00 20 { 0. 00 26) have been obtained with the Canada-France-Hawaii Telescope. NGC 3377 is kinematically similar to M 32: the central kinematic gradients are steep. The...
متن کاملOrigin of the metallicity distribution of the NGC 5128 stellar halo
Recent Hubble Space Telescope photometry in the nearby elliptical galaxy NGC 5128 shows that its halo field star population is dominated by moderately metal-rich stars, with a peak at [m/H] ≃ −0.4 and with a very small fraction of metal-poor ([m/H] < −1.0) stars. In order to investigate the physical processes which may have produced this metallicity distribution function (MDF), we consider a mo...
متن کاملA Color - Magnitude Diagram for a Globular Cluster in the Giant Elliptical Galaxy NGC 5128
The Hubble Space Telescope has been used to obtain WFPC2 (V, I) photometry for a large sample of stars in the outer halo of the giant elliptical NGC 5128, at a distance 4 Mpc beyond the Local Group. The globular cluster N5128-C44, at the center of the Planetary Camera field, is well enough resolved to permit the construction of a color-magnitude diagram (CMD) for it which covers the brightest t...
متن کاملThe Mass Distribution in the Elliptical Galaxy Ngc 3377: Evidence for a 2× 10-m⊙ Black Hole
This paper is a study of the mass distribution in the central 35 ≃ 1.7 kpc of the E5 galaxy NGC 3377. Stellar rotation velocity and velocity dispersion profiles (seeing σ∗ = 0. 20 – 0. 56) and V -band surface photometry (σ∗ = 0. 20 – 0. 26) have been obtained with the Canada-France-Hawaii Telescope. NGC 3377 is kinematically similar to M32: the central kinematic gradients are steep. There is an...
متن کاملThe Metallicity Distribution in the Halo Stars of NGC 5128: Implications for Galaxy Formation
We have used the Hubble Space Telescope to obtain WFPC2 (V, I) photometry for stars in the halo of NGC 5128, the nearest giant elliptical galaxy. The resulting color-magnitude diagram (CMD) of this field, which lies ∼ 21 kpc from the center of the galaxy, contains more than 10,000 stars and reaches almost 3 magnitudes down the red-giant branch (RGB). From the sharply defined RGB tip at I = 24.1...
متن کامل