Browsing by Author "Gómez, M"

Now showing 1 - 4 of 4
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    A direct distance to the Large Magellanic Cloud Cepheid HV 12198 from the infrared surface brightness technique
    (2000) Gieren, WP; Storm, J; Fouqué, P; Mennickent, RE; Gómez, M
    We report on the first application of the infrared surface brightness technique on a Cepheid in the Large Magellanic Cloud, the variable HV 12198 in the young globular cluster NGC 1866. From this one star, we determine a distance modulus of 18.42 +/- 0.10 (random and systematic uncertainty) to the cluster. When the results on further member Cepheids in NGC 1866 become available, we expect to derive the distance to the LMC with a +/-3%-4% accuracy, including systematic errors, from this technique.
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    Cepheid variables in the Large Magellanic Cloud cluster NGC 1866.: I.: New BVRI CCD photometry
    (2000) Gieren, WP; Gómez, M; Storm, J; Moffett, TJ; Infante, L; Barnes, TG; Geisler, D; Fouqué, P
    We report BV(RI)(C) CCD photometric data for a group of seven Cepheid variables in the young, rich cluster NGC 1866 in the Large Magellanic Cloud. The photometry was obtained as part of a program to determine accurate distances to these Cepheids by means of the infrared surface brightness technique and to improve the LMC Cepheid database for constructing Cepheid P-L and P-L-C relations. Using the new data together with data from the literature, we have determined improved periods for all variables. For five fundamental mode pulsators, the light curves are now of excellent quality and will lead to accurate distance and radius determinations once complete infrared light curves and radial velocity curves for these variables become available.
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    Similitude Pattern and Botanical Origin of the Chilean Propolis: [with 2 figures & 4 tables]
    (2004) Montenegro Rizzardini, Gloria; Mujica Rizzardini, Ana María; Peña, RC; Gómez, M; Serey, I; Timmermann, BN
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    The globular cluster system of NGC 4374
    (2004) Gómez, M; Richtler, T
    We study the globular cluster system (GCS) of the giant elliptical NGC 4374 (M 84) in the Virgo cluster using B and R photometry. The colour distribution is bimodal with peaks at B-R=1.11 and B-R=1.36, fitting well to those found in other early-type galaxies. The radial profile of the cluster number density is flatter than the galaxy light. Using the luminosity function we derive a distance modulus of mu=31.61+/-0.2, which within the uncertainty agrees with the distance from surface brightness fluctuations. Blue and red clusters show similar radial concentrations and azimuthal distributions. The total number of clusters is N=1775+/-150, which together with our distance modulus leads to a specific frequency Of S-N=1.6+/-0.3. This value is surprisingly low for a giant elliptical, but resembles the case of merger remnants like NGC 1316, where the low specific frequency is probably caused by the luminosity contribution of an intermediate-age population. A further common property is the high rate of type Ia supernovae which also may indicate the existence of a younger population. However, unlike in the case of NGC 1316, one cannot find any further evidence that NGC 4374 indeed hosts younger populations. The low specific frequency would also fit to a S0 galaxy seen face-on.