1203.1921
Theoretical transit spectra for GJ 1214b and other "Super-Earths"
Howe, Burrows
Transit spectra that allow for atmospheres with arbitrary proportions of common molecular species and haze. Tested with generic spectra, gave expected systematics and absorption features. Apply to GJ 1214b, which had H-rich or H-poor atmosphere and the water content ambiguous in observations. Analysis supports a H-rich atmosphere with a cloud or haze layer, although a H-poor model with <10% water is not ruled out. Ruled out classes are: H-rich atmosphere with no haze, H-rich atmosphere with a haze of 0.01um tholin particles, and H-poor atmosphere with major sources of absorption other than water. Propose an observational test to distinguish H-rich from H-poor, make predictions on spectral features of HD 97658b based on fits to GJ 1214b. Provide a library of theoretical transit spectra for super-Earths with a broad range of parameters to facilitate future comparison with anticipated data.
* Tholin: A hard, red-brownish substance, a heteropolymer molecule; don'e exist naturally on Earth (oxidation by atmosphere); formed by UV irradiation of simple organic compounds such as methane or ethane with molecular nitrogen. Orange-red hue of Titan's atmosphere, reddish surface on some Centaurs and outer asteroids may be explained by tholin.
1203.1925
HerMES: deep number counts at 250, 350, and 500 microns in the COSMOS and GOODS-N fields and the build-up of the cosmic infrared background
Bethermin et al
Herschel/SPIRE: provide confusion-limited maps of deep fields at 250, 350, and 500 um; only a small fraction of CIB can be resolved into individual sources. Goal: produce deep galaxy number counts and redshift distributions below the confusion limit, use to place strong constraints on the origins of the CIB and on models of galaxy evolution. Use 24um sources' (redshift, position and flux densities) as prior derive the number counts and redshift distributions of the bright SPIRE sources. For fainter SPIRE sources, reconstruct the number counts and the redshift distribution below the confusion limit using the deep 24um catalogs associated with photometric redshift and information provided by the stacking of these sources into the deep SPIRE maps. By integrating all these counts, studied the contribution of the galaxies to the CIB as a function of the flux density and redshift. Through stacking, managed to reconstruct the source counts per redshift slice down to 2mJy in the 3 SPIRE bands, which lies about a factor 10 below the 5 sigma confusion limit. Extrapolate counts to zero flux density in order to derive an estimate of the total contribution of galaxies to the CIB; values agree well with FIRAS absolute measurements, suggesting that the number counts and their extrapolation are sufficient to explain the CIB. Combine results with other works; estimate the energy budget contained in the CIB between 8 and 1000 um: 26 nW/m2/sr.
1203.1926
The arduous journy to black-hole formation in potential gamma-ray burst progenitors
Dessart, O'Connor, Ott
Death of fast-rotating massive stars evolved at low-metallicity, likely progenitors of long-duration GRBs (LGRBs). 1D+rotation tellar-collpase simulations, assess potential for formation of a BH and a Keplerian disk (collapsar--"failed" type Ib SNe) or a proto-magnetar. Accuracy of sim compromised by uncertainty in treatment of B-field and approximate handling of rotation. Find: nay the tastes rotating progenitors achieve sufficient compactness for BH, while the bulk of models possess a core density structure typical of ordinary core-collapse SN evolved without rotation, and at solar metallicity. Core compactness equally important as angular-momentum budget to condition BH formation (magneto-rotational explosion prevents BH formation); metallicity and the residual envelope mass must be compatible with observation of LGRB/SNe. Study suggests that BH formation is non trivial; there is room for accommodating both collapsars and proto-magnetars as LGRB progenitors, although probo-magnetars seem much more silty produced by current stellar-evolutionary models.
1203.1928
A robust constraint on cosmic textures from the cosmic microwave background
Feeney, Johnson, Mortlock, Peiris
Textures: type of topological defect produced during a cosmological phase transition in the early universe; leaves characteristic hot and cold spots in CMB. Rule out at 95% confidence, models that predict more than 6 detectable cosmic textures on the full sky.
1203.1930
Studying the kinematic asymmetries of disks and post-coalescence mergers using a new 'kinemetry' criterion
Bellocchi, Arribas, Colina
Use integral field spectroscopy for 4 LIRGs, all at ~70 Mpc (to avoid relative resolution effects). Two groups: isolated disks and post-coalescence mergers. Kinemetry (velocity field and velocity dispersion maps) use to discuss new criteria for distinguishing the two classes. Disks have lower kinematic asymmetries than post-coalescence mergers. This criteria would have classified post-coalescence systems as disks, which may have underestimated the merger/disk ratio.
1203.1931
Star-galaxy separation in the AKARI NEP deep field
Solarz,... Goto, et al
Some method to do star-galaxy separation using IR imaging only. 90% and 98% accuracy on identifying galaxies and stars, respectively (in comparison to optical image).
1203.1932
Impact of type Ia supernova ejecta on binary companions in the single-dengenerate scenario
Pan, Ricker, Taam
SNIa: thought to be caused by thermonuclear explosions of C-O WD in close binary systems. MS, RG, and He companion; symmetry-beraking effects of orbital motion, rotation of the non-degenerate star, and Roche-lobe overflow included in simulation. Find: dependence of the unbound stellar mass and kick velocity on the initial binary separation can be fitted by power-law relations. Process leading to the unbinding of matter is dominated by ablation (neglected in past analytical studies). Level of Ni/Fe contamination of the companion that results from the passage of the SNe ejecta is found to be 1e-5 Msun for MS, 1e-4 for He star, and 1e-8Msun for RG. Spinning MS companion star loses about half of its initial angular momentum during the impact.
1203.1941
A new extensive library of synthetic stellar spectra from PHOENIX atmospheres and its application to fitting VLT MUSE spectra
Husser, Kamann, Dreizler, Hauschildt
New library of synthetic spectra based on stellar atmosphere code PHOENIX; covers 500 to 55000 Angstrom with a resolution of R=1e5 in the optical and NIR, less in IR and UV. 2300K<Teff<8000K, 0<log(g)<6, -4<[Fe/H]<1 and -0.3<[alpha/Fe]<0.8. Will be extended to 25000K; self-consistent way of describing the micro turbulence of model atmospheres.
1203.1942
Reliable identifications of AGN from the WISE, 2MASS and Rosat all-sky surveys
Edelson, Malkan
Develop a statistic based on WISE, 2MASS and Rosat (IR and X-ray) to identify bright AGN candidates; 95% likely to be AGN (Seyfert 1, quasar or blazer). ~1000 new bright (J<16) AGN candidates. When full WISE dataset released, more candidates will be available.
1203.1996
The distribution of young stars and metals in simulated cosmological disk galaxies
Pilkington, Gibson, Jones
Age patterns orthogonal to spiral arms consistent as predicted by classical density wave theory and observations; Distribution of metals within a simulated ~0.1 L* disk presented, reinforcing the link between star formation, age-metallicity relation, and the metallicity distribution function.
1203.2026
On the smoothness of the interstellar extinction cure in the UV. Comparison with recent laboratory measurements of PAH mixtures
Steglich, ... et al
High-resolution spectra in 300-400 nm show no start absorption bands for large polyatomic molecules. In lab, PAH mixtures synthesized by IR laser pyrolysis and subsequent chemical extraction and size separation. Experimental results demonstrate that UV-visible absorption curves of PAH mixtures can be very smooth, displaying no sharp bands, if the molecular diversity is sufficiently high. The low fractional abundances of individual species prevent their detection on the basis of spectral fingerprints in the UV.
1203.2072
Inflationary perturbations in anisotropic, shear-free universes
Pereira, Carneiro, Marugan
Linear and gauge-invariant theory of cosmological perturbations in a class of anisotropic and shear-free space times is developed. Identify effective degrees of freedom during a generic slow-roll inflationary phase (anisotropic equivalent of the standard Mukhanov-Sasaki variables). Very similar equation of motion to FRW space-time with curvature, apart from the spectrum of the Laplacian, which exhibits the characteristic frequencies of the underlying geometry; the perturbations cannot develop arbitrarily large super-Hubble modes.
1203.2084
BLR kinematics and black hole mass in Markarian 6
Doroshenko et al
Coninuum and emission Balmer line intensities vary by more than 2x; lag between continuum and Hbeta emission is 21 days. Halpha is 27 days, but more uncertainty. Lag is slightly larger in the blue wing than in the red: a signature of infall gas motion. Measurements of Hbeta line width in combination with reverberation lag determine the BH mass at 1.8e8Msun. Consistent with AGN scaling relation between BLR radius and the optical continuum.
1203.2097
Constraints on single entity driven inflationary and radiation eras
Bouhmadi-Lopez, Chen, Liu
Model that attempts to fuse the inflationary era and the subsequent radiation dominated era under a unified framework for a smooth transition between the two; based on generalized Chaplygin gas.
1203.2138
Self-calibration of 3-point intrinsic alignment auto-correlations in weak lensing surveys
Troxel, Ishak
Explore the redshift dependencies of the IA and lensing bispectra in order to propose a self-calibration of the IA auto-correlations at the 3 pt level (GGI, GII, III), which can be well understood without the assumption of any particular IA model. Find that future WL surveys will be able to measure the distinctive IA redshift dependence over ranges of |z_p|<0.2. Using conservative estimates of photo-z accuracy, describe the 3-pt self-calibration technique for the total IA signal, which can be accomplished through lensing tomography of photo-z bin size ~0.01. Find: 3-pt self-calibration can function at the accuracy of the 2-pt technique with modest constraints in redshift separation. Allows the 3-pt IA auto-correlation self-calibration technique proposed here to significantly reduce the contamination of the IA contamination to the weak lensing bispectrum.
1203.2157
Fingerprinting Dark Energy III: distinctive marks of viscosity
Sapone, Majerotto
If DE is not a cosmological constant, then DE has two extra degrees of freedom: the sound speed and the anisotropic stress. If DE is inhomogeneous at scales of interest, then the gravitational potentials are modified and the evolution of the DM perturbations is also directly affected. Add anisotropic component to DE perturbations; solve analytically the equations of perturbations in the dark sector, find simple and accurate approximated solutions. Find: evolution of the density perturbations governed by an effective sound speed which depends on both the sound speed and the anisotropic stress parameter. Use solutions to look at the impact of the DE perturbations on the matter power spectrum and on the ISW effect on CMB.
Monitoring quasar color variability in stripe 82
Rogerson, Hall, MacLeod, Ivezic
BAL trough variability is due to cloud motion transverse to LoS. Rate of variability indicates velocity of the cloud, constrain cloud's distance from the central source; requires detailed spectroscopy during a variability event. Photometric monitoring of BAL quasar colors may potentially be used as an early warning system to trigger time-reqolved spectroscopic monitoring of BAL variability. Analyze both BAL and non-BAL color variability from stripe 82.
1203.2175
CARMA measurements of the Sunyaev-Zel'dovich effect in RXJ1347.5-1145
Plagge, et al
Demonstrate SZ effect imaging capabilities for CARMA, for the galaxy cluster. Capture the structure of this cluster over a wide range of angular scales (bulk properties to core morphology). Find: 9% of cluster's thermal energy associated with sub-arcmin-scale structure imparted by a merger, illustrating the value of high-resolution SZ measurements for per suing cluster astrophysics and for understanding the scatter in SZ scaling relations. Also find that the cluster's SZ signal is lower in amplitude that suggested by spherically-symmetric model from x-ray data, consistent with compression along the LoS relative to the plane of the sky. Discuss the impact of upgrades currently in progress that will further enhance CARMA's power as an SZ imaging instrument.
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