1206.3566
Kinematics of groups of galaxies in the Sloan Digital Sky Survey data release 7
Li, Mao, Han, Peng, Yang, Mo, van den Bosch
Velocity dispersion profile (VDP) for galaxy groups, using 16k groups for DR7. Groups split by group mass, then central galaxy M*. NFW profile + biased linear mass autocorrelation function describes the observed w_p(r_p), and provide accurate determination of real-space CCF xi(r) (cross-correlation wrt a reference sample, xi(r_p, pi)). Velocity dispersion flat within the virial radius (slight increase at innermost radius). Average VD within R_200 is a strongly increasing function of central galaxy mass. M*-sigma_v relation provides stringent constraints on both sigma_8 and sigma_ms, the dispersion in log(M*) of central galaxies at fixed halo mass. Data suggests sigma_8=0.86pm0.03 and sigma_ms=0.16pm0.03. Agrees with WL halo mass measurements.
1206.3567
Radiation magnetohydrodynamic simulations of protostellar collapse: protostelar core formation
Tomida et al
Run 3d RMHD, confirm that it matches 1d sims (spherical cores) because B-filed transfer angular momentum efficiently, but Ohmic dissipation enables the formation of the circumstellar disks in the vicinity of course as in previous MHD studies with barotropic approximation. Two types of outflows by B-fields in the resistive models.
1206.3568
Systematic simulations of modified gravity: symmetron and dilation models
Brax et al
Study NL structure formation in dilaton and symmetron modified gravity models (N-body).
1206.3569
LAMOST spectral survey
Zhao, Zhao, CHu, Jing, Deng
LAMOST (Large sky Area Multi-Object fiber Spectroscopic Telescope) ready for main science survey: discovery of the first generation stars in the Galaxy, pinning down the formation and evolution history of galaxies and its central massive BH, looking for signatures of DM distribution, and possible sub-strucures in the MW halo. National and international collaboration. Two major components: LAMOST ExtraGAlacticSurvey (LEGAS) and LAMOST Experiment for Galactic Understanding and Exploration (LEGUE).
1206.3571
Galaxy evolution in groups and clusters: satellite star formation histories and quenching timescales in a hierarchical Universe
Wetzel, Tinker, Conroy, van den Bosch
Examine SFH and quenching timescales of satellites of M*>5e9 Msol at z~0. Empirically find `central` SFR, figure out the time of first satellite infall, empirically constrain the amount and efficiency of satellite quenching as a function of satellite and host halo mass. Find: satellite quenching is the dominant process for building up all quiescent galaxies at M*<1e10Msol. Find 'delayed-then-rapid' quenching scenario: first 2-4 Gyr after infall unaffected, then SF quenches rapidly (<0.8Gyr decay time). Quenching timescales shorter for more massive satellites, but do not depend on host halo mass. Group preprocessing is responsible for up to half of quenched satellites in massive clusters. Satellites experience significant stellar mass growth after infall due to the time delay; a key reason for the success of the sub halo abundance matching technique.
1206.3573
A stellar mass threshold for quenching of field galaxies
Geha, Blanton, Yan, Tinker
For galaxies with stellar mass < 1e9Msun, ending SF requires a presence of a more massive neighbor, providing a stringent constraint on models of SF feedback.
[Lots of LEGUE papers]
1206.3579
On the shapes and structures of high-redshift compact galaxies
Chevance et al
Kolmogorov-Smirnov test: a non-parametric test for the equality of continuous, 1D PDF. Quantifies the distance between the empirical distribution function of the sample and the cumulative distribution function of the reference distribution.
From SDSS, select 40k high-z compact galaxies, show that ellipticity distribution consistent with local early types, but Sersic indices distribution consistent with local disk-types. Basic structures of high-z compact galaxies do not closely resemble any single local galaxy population.
1206.3583
Stochastic flights of propellers
Pan, Rein, Chiang, Evans
Saturn ring "propellers" around km-sized moonlets in A-ring. Motion deviate from Keplerian orbits having constant semimajor axis. Inferred orbital migration is known to switch sign [?]. Shoe: orbital longitudes of the propeller Bleriot is consistent with time-integrated random walk (i.e., migration pattern is stochastic). Show that ring particles must be 10-20m in radius, and also supported independently by occultation analysis.
1206.3611
Discovery of six high-redshift quasars with the Lijiang 2.4m telescope and MMT
Wu et al
Quasars with z>4 are rare. 6 new quasars with i < 19.5 and 2.4<z<4.6, selected from J-K/i-Y color criterion, and from SDSS/UKIDSS (NIR) photo-z. 6/9 candidates were found to be z>3.6.
1206.3656
Testing potential new sites for optical telescopes in Australia
Hotan, Tingay, Glazebrook
Combine meterological IR data to ascertain cloud coverage rates, and combine with Digital Elevation Model. Find: best sites within Australia are likely to be on the highest mountains. Seeings can be as good as Siding Spring [where? what seeing?], with significantly more observing time (x2 clear nights).
1206.3640
The study of climate on alien worlds
Heng
Characterizing atmospheres beyond the Solar System.
1206.3646
Type-Ia Supernova remnant shell at $Z=3.5$ seen in the three sightlines toward the gravitationally lensed Qso B1422+231
Hamano et al
The spectra for a multiply-lensed QSO shows SNIa remnant.
1206.3665
A stellar test of the physics of unification
Vieira, Martins, Monteiro
Polytropic process: a thermodynamic process that obeys the relation pV^n = C
Use MS stars as probes of fundamental physics: study its sensitivity to variations of the gravitational, strong and EW coupling constants in the context of unification scenarios. Quantify the sensitivity of the SUn's interior temperature to these variations.
1206.3690
A six-parameter space to describe galaxy diversification
Fraix-Burnet, Chattopadhyay, Chattopadhyay, Davoust, Thuillard
Study sample of 424 E-type galaxies described by 25 parameters (10 Lick indices) to identify the most structuring parameters and determine an evolutionary classification of these objects. Four independent statistical methods used: Principal component analysis, K-means cluster analysis, Minimum Contradiction Analysis and Cladistics.
1206.3710
Radiative transfer on hierarchial grids
Lunttila, Juvela
New method for calculating the scattered flux that employs the grid structure to speed up the computation. Compared with existing method, similar results, but runs faster.
1206.3723
DC circuit poered by orbital motion: magnetic interactions in compact object binaries and exoplanetary systems
Lai
T Tauri stars: class of variable stars, pre-main sequence, found near molecular clouds and identified by their optical variability and strong chromospheric lines.
Unipolar induction DC circuit model [???] applied to binary systems. Show upper limit to the B interaction torque and energy dissipation rate in such model. Find that in coalescing NS binaries, B interactions produce negligible correction to the phase evolution of the gravitational waveform, even for magnetar-like field strengths; but E dissipation may still give rise to EM radiation prior to the final merger. For ultra-compact WD binaries, the DC circuit does not provide adequate energy dissipation to explain the observed X-ray luminosities of several sources. For close-in Jupiters or suer-Earths, B torque and dissipation are negligible, except during the early T-Tauri phase, when the B field is > 1e3 G.
1206.3725
Cosmic antigravity
Dolgov
Gravitational repulsion in GR, astronomical data in support described. Vacuum energy problem emphasized, possible solution indicated.
1206.3750
The significance of ultracompact minihalos as the astrophysical sources
Yang et al
Assume DM annihilation happens, then it should be strong in ultra-compact mini haloes.
1206.3779
The vertical X-shaped structure in the Milky Way: Evidence from a simple boxy bulge model
Li, Shen
Existence of vertical X-shaped structure in the Galactic bulge suggests that the formation of the MW bulge is shaped mainly by internal disk dynamical instabilities.
1206.3788
The galactic halo in mixed dark cosmologies
Anderhalden, Diemand, Bertone, Maccio, Schneider
A possible solution to the small scale problems of CDM: DM consists of cold and warm components. [what's the problem again?]
1206.3797
The history and environment of a faded quasar: Hubble space telescope observations of Hanny's Voorwerp and IC 2497
Keel et al
Some of the strong ionization emission lines are from recent SF. Independence of ionization and surface brightness suggests that substantial spatial structure remains unresolved. Picture: ionization echo from an AGN whose ionizing luminosity has dropped by a factor >100 or more within the last 1-2e5 years.
1206.3808
The structures of distant galaxies V: the evolution of galaxy structure in stellar mass at z<1
Lanyon-Foster, Conselice, Merrifield
Study stellar mass distribution with morphology. Stellar mass trace the underlying distribution of matter, minimizes the effects of SF and dust on the appearance and structure of a galaxy. GOODS field study of z<1 galaxy structures; stellar mass maps and M/L ratio maps. Early and late-type clearly separated in parameters, but cannot easily distinguish SF and dynamically disturbed systems. Evidence for active bulge formation?
1206.3839
Centaurus A as a point source of Ultra-High energy cosmic rays
Kim
Probe the possibility that Cen A is a point source of UHECR through statistical analysis of arrival direction distribution. Effect of intergalactic B-fields on the bending of UHECR parameterized by gaussian smearing angle theta_s. Fraction is 0.1, theta_s is 5 deg, maximum probability 0.29. If this is true, then implies 10nG intergalactic B-field in the vicinity of Cen A.
1206.3840
Initial results from the Nobeyama molecular gas observations of distant bright galaxies
Iono et al
Initial results from the CO survey using Nobeyama 45m telescope [really? 45m?], submm observations, with spectrometer.
1206.3842
On rings and streams in the galactic anti-center
Li, Newberg, Carlin, ... et al
Monoceros ring: a long, complex, ringline filament of stars that wrap around the MW 3 times. Consiste of a stellar stream from Canis Major Dwarf Galaxy by tidal forces; first reported in SDSS.
Confirm at least 3 separate low-latitude over-densities of blue F turnoff stars near the MW anti-center [what's that?]: the Monoceros Ring, plus possibly normal thick disk stars at the same location. ...
1206.3843
A uniformly selected sample of low-mass Black holes in Seyfert 1 galaxies
Donge, Ho, Yuan, Wang, Fan, Zhou, Jiang
Define a sample of 309 type 1 AGNs with BH masses in the range 8e4 to 2e6 Msun (median 1.2e6 solar mass), using the virial mass estimator on the broad Halpha line. Picks up AGNs with low accretion rates. Suggests a significant fraction of low-mass BHs in the local Universe are accreting at low rates.
1206.3845
Sizing up partially-depleted galaxy cores
Dullo, Graham
Modeled the inner surface brightness profiles of 39 alleged 'core' galaxies. Additional nuclear components simultaneously modeled, if present. Some (18%) have low Sersic values of n<4 [?]. ... [I don't understand the significance of this study. at all.]
1206.3888
Probing non-spherical dark haloes in the galactic dwarf galaxies
Hayashi, Chiba
Axisymmetric mass models for dSph in MW to obtain plausimle limits on the non-spherical structure of their dark haloes; motivated by the observed luminous parts of dSphs are actually non-spherical, and CDM predicts non-spherical haloes as well. Find: most of the dSphs yield oblate and flattened dark halos, irrespective of assumed density profiles in their central parts. Also find total mass of dSphs enclosed within a spheroid with major-axis length of 300pc varies from 1e6 to 1e7, contrary to conclusion from spherical models. Find dark haloes may be more flattened than N-body predictions.
1206.3905
Reexamination of the infrared excess-Ultraviolet slope relation of local galaxies
Takeuchi, Yuan, Ikeyama, Murata, Inoue
The relation between the infrared excess (IRX, ratio of IR and UV flux densities) and the slope of the UV spectrum (beta) of galaxies playes a fundamental role in the evaluation of the dust attenuation of SF galaxies, especially at high z. Reexamine GALEX and AKARI data, find consistent result as previous measurements.
1206.3907
On the excess of ultra-high energy cosmic rays in the direction of Centaurus A
Liu, Wang, Wang, Taylor
Another paper about Cen A excess. CR > 55EeV within 18 deg of the direction of radio galaxy Centaurus A. Simulation propagation; Find that only particles of nuclear charge Z<10 can avoid being deflected outside of the 18 deg window. Plausible scenario: they consist of intermediate-mass nuclei. Chemical composition of CRs further constrained by lower-energy CRs of the same rigidity [?]. CR acceleration in the lobes of Cen A is not favored, while acceleration in the stellar winds that are rich in intermediate-mass nuclei could meet the requirement. Observed excess may originate from CR accelerators induced by stellar explosions in the SF regions of Cen A and/or the cluster located behind Cen A.
1206.3972
Care and feeding of frogs
Pan, Chiang
Residuals of the best-observed Saturn A-ring propeller, "Bleriot", appear consistent with a sinusoid of period ~4 years. Propeller moonlest librate in frog resonances (Pan and Chiang 2010) with co-orbiting ring material. Use numerical experiments to extend the frog model. Find frog librations can persist only if t_diff (time for a ring particle to travel from conjunction with the moonlet to the end of the gap) exceeds the frong libration period P_lib. Need more accurate treatments of feedback.
1206.3998
Cyclic and Ekpyrotic universes in modified Finsler Osculateing gravity on tangent Lorentz bundles
Stavrinos, Vacaru
Consider models of accelerating universe elaborated for Finsler like gravity theories constructed on tangent bundles to Lorentz manifolds. [uuuugh]
1206.4014
2D mapping of young stars in the 180 pc of NGC 1068: correlation with moloecular gas ring and stellar kinematics
Storchi-Bergmann et al
Use integral field spectroscopy in the NIR. ...
1206.4028
On the use of Ly-alpha emitters as probes of reionization
Jensen et al
Numerical sims to study the effects of the patchiness of a partly reionized IGM on the observability of Ly-alpha emitters (LAEs) at z~6. Find: if the observed changes in LAE luminosity functions are EW distributions between z~6-7 are to be explained by an increased IGM neutral fraction alone, require an extremely late and rapid reionization scenario, where the universe was 40% ionized at z=7, 50% at 6.5, and 100% at z=6. This is in conflict with other observations, suggesting that intrinsic LAE evolution at z>6 cannot be completely neglected. Show how 2pt correlation function can provide more robust constraints once future observations obtain larger LAE samples.
1206.4031
Stellar archaeology in the galactic halo with ultra-faint dwarfs: VII. Hercules
Musella
Find 10 pulsating variable stars in Hercules. Find metallicity. The CMD and RR Lyrae stars indicate presence of a population as old and metal-poor as the Galactic globular clusters M68.
[Tue **/72] Jun 19
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