San Francisco State University

About: San Francisco State University is a education organization based out in San Francisco, California, United States. It is known for research contribution in the topics: Population & Planet. The organization has 5669 authors who have published 11433 publications receiving 408075 citations. The organization is also known as: San Francisco State & San Francisco State Normal School.

Planetary Companions to HD 12661, HD 92788, and HD 38529 and Variations in Keplerian Residuals of Extrasolar Planets

Abstract: Precision Doppler observations at the Lick and Keck observatories have revealed Keplerian velocity variations in the stars HD 12661, HD 92788, and HD 38529. HD 12661 (G6 V) has an orbital period of 252.7 ± 2.7 days, velocity semiamplitude K = 88.4 ± 2.0 m s-1, and orbital eccentricity e = 0.23 ± 0.024. Adopting a stellar mass of 1.07 M☉, we infer a companion mass of M sin i = 2.79 MJ and a semimajor axis of a = 0.79 AU. HD 92788 (G5 V) has an orbital period of 326.7 ± 3.2 days, velocity semiamplitude K = 99.9 ± 2.4, and orbital eccentricity e = 0.30 ± 0.06. The adopted stellar mass of 1.06 M☉ yields a companion mass of M sin i = 3.34 MJ and a semimajor axis of a = 0.95 AU. HD 38529 (G4 IV) has an orbital period of 14.3 ± 0.8 days, velocity semiamplitude K = 53.8 ± 2.0 m s-1, and eccentricity e = 0.27 ± 0.03. The stellar mass of 1.4 M☉ sets M sin i = 0.77 MJ, with a semimajor axis of a = 0.13 AU for this companion. In addition to the 14.3 day periodicity, the velocity residuals for HD 38529 show curvature over the three years of observations. Based on a measurement of Ca II H and K emission, all three stars are chromospherically inactive. Based on both spectral synthesis modeling and narrowband photometry, HD 12661, HD 92788, and HD 38529 all appear to be metal-rich stars, reinforcing the correlation of high metallicity in the host stars of gas giant extrasolar planets. We examine the velocity residuals to the Keplerian fits for a subsample of 12 planet-bearing stars that have been observed longer than two years at the Lick Observatory. Five of the 12 (Ups Andromedae, τ Boo, 55 Cnc, HD 217107, and HD 38529) exhibit coherent variations in the residual velocities that are consistent with additional companions. Except for Upsilon Andromedae, the source of the velocity variation remains speculative pending completion of one full orbit. GJ 876 exhibits residual velocities with high rms scatter (24 m s-1), lacking identifiable coherence. The residual velocities for six of the 12 stars (51 Peg, 70 Vir, 16 Cyg B, ρ CrB, 47 UMa, and HD 195019) exhibit rms velocity scatter of ~7 m s-1, consistent with errors. The residual velocity trends suggest that known planet-bearing stars appear to harbor a distant (>3 AU) detectable companion more often than other stars in our planet survey.

The thrill of victory and the agony of defeat: spontaneous expressions of medal winners of the 2004 Athens Olympic Games.

Abstract: Facial behaviors of medal winners of the judo competition at the 2004 Athens Olympic Games were coded with P. Ekman and W. V. Friesen's (1978) Facial Affect Coding System (FACS) and interpreted using their Emotion FACS dictionary. Winners' spontaneous expressions were captured immediately when they completed medal matches, when they received their medal from a dignitary, and when they posed on the podium. The 84 athletes who contributed expressions came from 35 countries. The findings strongly supported the notion that expressions occur in relation to emotionally evocative contexts in people of all cultures, that these expressions correspond to the facial expressions of emotion considered to be universal, that expressions provide information that can reliably differentiate the antecedent situations that produced them, and that expressions that occur without inhibition are different than those that occur in social and interactive settings.

Ultraviolet tails and trails in cluster galaxies: a sample of candidate gaseous stripping events in Coma

Abstract: We have used new deep observations of the Coma cluster from Galaxy Evolution Explorer to visually identify 13 star-forming galaxies with asymmetric morphologies in the ultraviolet (UV). Aided by wide-field optical broad-band and Hα imaging, we interpret the asymmetric features as being due to star formation within gas stripped from the galaxies by interaction with the cluster environment. The selected objects display a range of structures from broad fan-shaped systems of filaments and knots (‘jellyfish’) to narrower and smoother tails extending up to 100 kpc in length. Some of the features have been discussed previously in the literature, while others are newly identified here. We assess the ensemble properties of the sample. The candidate stripping events are located closer to the cluster centre than other star-forming galaxies; their radial distribution is more similar to that of all cluster members, dominated by passive galaxies. The fraction of blue galaxies which are undergoing stripping falls from 40 per cent in the central 500 kpc to less than 5 per cent beyond 1 Mpc. We find that tails pointing away from (i.e. galaxies moving towards) the cluster centre are strongly favoured (11/13 cases). From the small number of ‘outgoing’ galaxies with stripping signatures, we conclude that the stripping events occur primarily on first passage towards the cluster centre, and are short-lived compared to the cluster crossing time. Using galaxy infall trajectories extracted from a cosmological simulation, we find that the observed fraction of blue galaxies undergoing stripping can be reproduced if the events are triggered at a threshold radius of ∼1 Mpc and detectable for ∼500 Myr. Hubble Space Telescope images are available for two galaxies from our sample and reveal compact blue knots coincident with UV and Hα emission, apparently forming stars within the stripped material. Our results confirm that stripping of gas from infalling galaxies, and associated star formation in the stripped material, is a widespread phenomenon in rich clusters. Deep UV imaging of additional clusters is a promising route to constructing a statistically powerful sample of stripping events and constraining models for the truncation of star formation in clusters.

Deep MMT* Transit Survey of the Open Cluster M37. II. Variable Stars

Abstract: We have conducted a deep (15 r 23), 20 night survey for transiting planets in the intermediate-age (~550 Myr) open cluster M37 (NGC 2099) using the Megacam wide-field mosaic CCD camera on the 6.5 m MMT. In this paper we present a catalog and light curves for 1445 variable stars; 1430 (99%) of these are new discoveries. We have discovered 20 new eclipsing binaries and 31 new short-period (P < 1 day ) pulsating stars. The bulk of the variables are most likely rapidly rotating young low-mass stars, including a substantial number (500) that are members of the cluster. We identify and analyze five particularly interesting individual variables, including a previously identified variable that we suggest is probably a hybrid γ Doradus/δ Scuti pulsator, two possible quiescent cataclysmic variables, a detached eclipsing binary (DEB) with at least one γ Doradus pulsating component (only the second such variable found in an eclipsing binary), and a low-mass (MP ~ MS ~ 0.6 M☉) DEB that is a possible cluster member. A preliminary determination of the physical parameters for the DEB+γ Doradus system yields MP = 1.58 ± 0.04 M☉, MS = 1.58 ± 0.04 M☉, RP = 1.39 ± 0.07 R☉, and RS = 1.38 ± 0.07 R☉.

A review of 2000 years of paleoclimatic evidence in the Mediterranean

Abstract: The integration of climate information from instrumental data and documentary and natural archives; evidence of past human activity derived from historical, paleoecological, and archaeological records; and new climate modeling techniques promises major breakthroughs for our understanding of climate sensitivity, ecological processes, environmental response, and human impact. In this chapter, we review the availability and potential of instrumental data, less well-known written records, and terrestrial and marine natural proxy archives for climate in the Mediterranean region over the last 2000 years. We highlight the need to integrate these different proxy archives and the importance for multiproxy studies of disentangling complex relationships among climate, sea-level changes, fire, vegetation, and forests, as well as land use and other human impacts. Focusing on dating uncertainties, we address seasonality effects and other uncertainties in the different proxy records. We describe known and anticipated challenges posed by integrating multiple diverse proxies in high-resolution climate-variation reconstructions, including proxy limitations to robust reconstruction of the natural range of climate variability and problems specific to temporal scales from interannual to multicentennial. Finally, we highlight the potential of paleo models to contribute to climate reconstructions in the Mediterranean, by narrowing the range of climate-sensitivity estimates and by assimilating multiple proxies.