1204.4180
Construction of a calibrated probabilistic classification catalog: Application to 50k variable sources in the all-sky automated survey
Richards, Starr, Miller, Bloom, Butler, Brink, Crellin-Quick
Need well-calibrated probabilistic classification catalogs for minimum human intervention. Describe a process to produce a probabilistic classification catalog of variability with machine learning from a multi-epoch photometric survey. In addition to producing accurate classifications, show how to estimate calibrated class probabilities; probability calibration is important. Feature-based anomaly detection for discovery of objects that do not fit the predefined class taxonomy. Apply methods to sources observed by the All Sky Automated Survey, present the catalog (28-class probabilistic classification catalog of >50k sources. Error rate <20% (estimated), demonstrate class posterior probabilities that are reasonably calibrated. Classification code publicly available.
1204.4182
SOSS: a moving object image search tool for asteroid precovery
Gwyn, Hill, Kavelaars
Code available. Run on CFHT MegaCam archive.
1204.4184
A fundamental problem in the theory of low mass galaxy evolution?
Weinmann, Pasquali, Oppenheimer, Finlator, Mendel, Crain, Maccio
SAM and observed number density evolution of low mass galaxies have dramatic differences. While predicting z=0 numbers correctly, actual evolution happens late. Found same results with hydrosims. Underlying cause of discrepancy: presence of a positive correlation between sSFR and stellar mass in both SAM and Hydro models. Similar positive correlation found between specific DM accretion rate and the halo mass, model galaxies are growing in a way that follows the growth of their host haloes too closely. Need to find a mechanism that decouples the growth of low mass galaxies, which occurs at late times, from the growth of their host haloes, which occurs at early times. [low mass galaxies grow at late time, host halo mass accrete early time]. Current form of SF driven feedback implemented in most galaxy formation models is unlikely to achieve this goal, owing to its fundamental dependence on host halo mass and time.
1204.4185
Stable counteralignment of a circumbinary disc
Nixon
Gas accreting onto SMBH binary: can have any disk orientation wrt binary angular momentum. Disk may wholly counteralign; the same disc may conteralign in inner regions and on longer timescales, coaling its outer regions. For typical disc parameters, a misaligned circumbinary disc is likely to wholly co- or counter-align with the binary plane, because the binary angular momentum dominates the disc angular momentum; while in extreme scenarios the disc may simultaneously co- and counter- align. Coplanar prograde circumbinary discs are stable. Retrogrades are also stable, of coplanar. A chaotic accretion event onto and SMBH binary will therefore result in a coplanar circumbinary disc that is ether prograde or retrograde with respect to the binary plane.
1204.4190
Milky way star forming complexes and the turbulent motion of the galaxy's molecular gas
Lee, Murray, Rahman
Expansion of bubbles is a major driver of the turbulent motion of the inner MW molecular gas. These bubbles (24 sources) emit half the ionizing luminosity of the Galaxy.
1204.4194
CANDELS: correlations of SEDs and morphologies with star-formation status for massive galaxies at z~2
Wang, Huang, Faber, ... Dekel, ... Grogin, et al
Study of SED, morphologies and SF for an IRAC-selected extremely red object sample in the GOODS CDF-S field. Use HST/WFC3 NIR imaging from CANDELS, as well as Chandra 4Ms (deepest available) X-ray data. 133 objects with [3.6um]=21.5 limiting mag, approximately complete for galaxies with M>1e11 Msun at 1.5<z<2.5. Morphology consistent with color classification. IR color classification consistent with rest-frame color classification. Find quiescent and SF galaxies are well separated in the morphology parameter diagram measuring their concentration and clumpiness: galaxy types split by Gini coefficient = 0.58. SF quenching process must lead to or be accompanied by the increasing galaxy concentration. Disks are commonly seen in this massive galaxy sample at 1.5<z<2.5: 30% of quiescent galaxies and 70% of SF galaxies with M*>1e11 Msun have disks in their rest-frame optical morphologies. The prevalence of these extended, relatively undisturbed disks challenges the merging scenario as the main mode of massive galaxy formation.
1204.4206
Revealing companions to nearby stars with astrometric acceleration
Tokovinin, Hartung, Hayward, Makarov
51 Hipparcos astrometric binaries observed with AO, directly resolving 17 sub-arcsecond companions and 7 wider ones. Compare with simulated binary population. Fraction of resolved companions slightly lower than expected from binary statistics; about 10% of astrometric companions could be "dark" (WD and late M-dwarfs). Several binars found with companions too wide to explain the acceleration. Reanalysis shows that some acceleration solution in the original Hipparcos catalog are spurious.
1204.4210
On the link between central black holes, bar dynamics, and dark matter halos in spiral galaxies
Treuthardt, Seigar, Sierra, Al-Baidhany, Salo, Kennefick, Kennefick, Lacy
SMBH mass and spiral pitch angle (P) related--evidence that SMBHs are tied to the overall secular evolution of a galaxy. Discovery of SMBHs in late-type galaxies with littel or no bulge suggests that an underlying correlation between the DM halo concentration and SMBH exists, rather than between the bulge mass and MBH. Meausre P using 2d FFT and estimate the bar pattern speeds of 40 barred spiral galaxies from the Carnegie-Irvine Galaxy Survey. Estimate gravitational potential from Ks band images, produce dynamical simulation models. Pattern speed allow the ID those galaxies with ow central dark halo densities, or fast rotating bars, while P provides and estimate of MBH. Find that a wide range of MBH exists in galaxies with low central DM halo densities, which appears to support other theoretical results. Find: galaxies with low central dark halo densities appear to follow more predictable trends in P versus deVauc morphological type (T) and bar strength vs. T than barred galaxies in general. The empirical relationship between MBH and total mass of a galaxy Mtot predict the minimum Mtot that will be observationally measured of the fast bar galaxies. ...
1204.4219
An absence of neutrinos associated with Cosmic ray acceleration in gamma-ray bursts
IceCube Collaboration
GRB a leading candidate for acceleration of UHE CRs; should be accompanied by TeV neutrinos in proton-photon interactions during acceleration. 2 years of IceCube detector produced no evidence for this neutrino emission, placing strong constraints on models of neutrino and CR production in these sources.
1204.4234
Candidate stellar occultations by large trans-neptunian objects up to 2015
Assafin et al
2717 stellar occultation candidates for TNOs (Eris, Haumea, Ixion, Makemake, Orcus, Quaoar, Sedna, Varuna, 2002 TX300 and 2003 AZ84) for 2011-2015, for stars of R=19 down to about 21. Data available on web.
1204.4236
The spin of late-type galaxies at redshifts $z \le 1.2$
Cervantes-Sodi, Hernandez, Hwang, Park, Le Borgne
Study the evolution of the galactic spin using data of high z galaxies in GOODS survey. Distribution consistent with that found for nearby galaxies. Find no sign of redshift evolution in the range 0.4<z<1.2. Mass and environmental dependence of the spin in the high-z galaxies similar to that of low-z galaxies, showing a strong dependence on mass (low mass systems present higher lambda_d values than high-mass ones, with no significant dependence on the environmental density). Individual disc galaxies might occasionally suffer from strong evolution, they evolve in such a way that the overall spin distribution of the galactic population remains constant from z~1 to the present epoch.
1204.4241
Scale-dependent bias of galaxies and mu-type distortion of the cosmic microwave background spectrum from single-field inflation with a modified initial state
Ganc, Komatsu
Phenomenological consequences of a modification of the initial state of a single inflationary field. Observe a k^-3 signature in LSS [in bispectrum?]
1204.4261
Differential rotation of main-sequence dwarfs: predicting he dependence on surface temperature and rotation rate
Kitchatinov, Olemskoy
Gyrochronology and theory used to reduce the number of input parameters of differential rotation models. Predicts: surface differential rotation as a function of surface temperature and rotation period, both which can be defined observationally. Tendency for the differential rotation to increase with temperature. Increase much steeper for late F-stars compared to G- and K-dwarfs. Slow and fast rotation regimes for internal stellar rotation identified. Star attains maximum differential rotation at rotation rates intermediate between two regimes. Amplitude of meridional flow increases with surface temperature and rotation rate. Structure of flow changes considerably between slow and fast rotation. The flow in rapid rotators concentrated in the boundary layers near the top and bottom of the convection zone with very weak circulation in between.
1204.4265
Evolution of active galactic nuclei
Merloni, Heinz
SMBH: discuss how evolution is constrained, probed by AGN. Initial study were "demography" for LSS studies, but strong evolution in luminosity and number density hindered attempts to derive cosmological parameters. AGN luminosity functions, relation of SMBH growth the environment (scaling relations and limits on the evolution of the SMBH mass function). Physical models of AGN feedback. First SMBH formation, role of BH in high-z universe discussed.
1204.4293
Fast calculation of the weak lensing aperture mass statistic
Leonard, Piers, Starck
Fully explore the formalism underlying the aperture mass statistic. Demonstrate that the M_ap is formally identical to a wavelet transform at a specific scale; filter functions most frequently used in M_ap studies are not ideal (being non-local in both real and Fourier space). In contrast, the wavelet formalism offers a number of wavelet functions that are localized both in real and Fourier space, yet similar to the 'optimal' aperture mass filters commonly used. For an number of wavelet functions (e.g., starlet), a number of fast algorithms exist to compute the wavelet transform. Significant advantages over the usual aperture mass algorithm when it comes to image processing time, demonstrating speed-up factors of 5-1200 for aperture radii in the range 2 to 64 pixels.
1204.4314
Galileons on Trial
Appleby, Linder
Galileon gravity: predictions for the combination of cosmic expansion and growth history are distinct from LCDM, approaching LCDM in one causes deviations in the other. This tension allows it to severely disfavor the entire class of minimally coupled standard Galileon gravity.
1204.4320
The search for supernova-produced radionuclides in terrestrial deep-sea archives
Feige, Wallner, Winkler, Merchel, et al
Enhanced concentration of 60Fe found in a deep ocean's crust in 2004 in a layer corresponding to an age of ~2Myr. Two suitable marine sdiment cores from the south Australian basin and estimate the intensity of a possible signal of the SNe-produced radionuclides 26Al, 53Mn, 60Fe and the pure r-process element 244Pu in these cores.
* this abstract doesn't give the results!!! From the conclusion: concentration compared to long-living 10Be to date the sediments. Al and Mn challenigng to clearly distinguish from a SN signal. Sediment cores split into sections of 1cm length (3kyr). ... Not yet clear how dust is formed in a SN ejecta, and how the grains are transported to Earth. Radionuclides only able to overcome the ram pressure of the solar wind and interplanetary B-field if they are condensed into dust particles.
1204.4437
Inner polar rings and disks: observed properties
Moiseev
47 galaxies of all morphological types (E to Irr), with inner regions that have polar (or strongly inclined) disks and rings, compiled from literature. Radii of the majority of them do not exceed 1.5 kpc. Polar structure equally common in barred and unbarred galaxies. If a galaxy has a bar (or a triaxial bulge), this leads to the polar disk stabilization (axis of rotation usually coincides with the major axis of the bar. More than two thirds of all considered galaxies reveal signs of recent interaction or merging. Direct relation between the external environment and the presence of an inner polar structure.
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