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Articles 1 - 5 of 5
Full-Text Articles in Physical Sciences and Mathematics
Hst Morphologies Of Z~2 Dust Obscured Galaxies Ii. Bump Sources, R. Shane Bussmann, Arjun Day, Jennifer Lotz, Lee Armus, Michael J. I. Brown, Peter Eisenhardt, James L. Higdon, Sarah J.U. Higdon, Buell T. Januzzi, Emeric Le Floc'h, J. Melbourne, B. T. Soifer, Daniel Weedman
Hst Morphologies Of Z~2 Dust Obscured Galaxies Ii. Bump Sources, R. Shane Bussmann, Arjun Day, Jennifer Lotz, Lee Armus, Michael J. I. Brown, Peter Eisenhardt, James L. Higdon, Sarah J.U. Higdon, Buell T. Januzzi, Emeric Le Floc'h, J. Melbourne, B. T. Soifer, Daniel Weedman
Department of Physics and Astronomy Faculty Publications
We present Hubble Space Telescope imaging of 22 ultra-luminous infrared galaxies (ULIRGs) at z 2 with extremely red R – [24] colors (called dust-obscured galaxies, or DOGs) which have a local maximum in their spectral energy distribution (SED) at rest-frame 1.6 μm associated with stellar emission. These sources, which we call "bump DOGs," have star formation rates (SFRs) of 400-4000 M ☉ yr–1 and have redshifts derived from mid-IR spectra which show strong polycyclic aromatic hydrocarbon emission—a sign of vigorous ongoing star formation. Using a uniform morphological analysis, we look for quantifiable differences between bump DOGs, power-law DOGs (Spitzer …
Erasing Dark Matter Cusps In Cosmological Galactic Halos With Baryons, Emilio Romano-Diaz, Isaac Shlosman, Yehuda Hoffman, Clayton Heller
Erasing Dark Matter Cusps In Cosmological Galactic Halos With Baryons, Emilio Romano-Diaz, Isaac Shlosman, Yehuda Hoffman, Clayton Heller
Department of Physics and Astronomy Faculty Publications
We study the central dark matter (DM) cusp evolution in cosmologically grown galactic halos. Numerical models with and without baryons (baryons+DM, hereafter BDM model, and pure DM, PDM model, respectively) are advanced from identical initial conditions, obtained using the Constrained Realization method. The DM cusp properties are contrasted by a direct comparison of pure DM and baryonic models. We find a divergent evolution between the PDM and BDM models within the inner few × 10 kpc region. The PDM model forms an R−1 cusp as expected, while the DM in the BDM model forms a larger isothermal cusp R …
A 500 Kpc Hi Extension Of The Virgo Pair Ngc4532/Ddo137 Detected By The Arecibo Legacy Fast Alfa (Alfalfa) Survey, Rebecca A. Koopmann, Riccardo Giovanelli, Martha P. Haynes, Brian R. Kent, Thomas J. Balonek, Noah Brosch, James L. Higdon, John J. Salzer, Oded Spector
A 500 Kpc Hi Extension Of The Virgo Pair Ngc4532/Ddo137 Detected By The Arecibo Legacy Fast Alfa (Alfalfa) Survey, Rebecca A. Koopmann, Riccardo Giovanelli, Martha P. Haynes, Brian R. Kent, Thomas J. Balonek, Noah Brosch, James L. Higdon, John J. Salzer, Oded Spector
Department of Physics and Astronomy Faculty Publications
We report the discovery of a ~500 kpc H I extension southwest of the Virgo Cluster H I-rich pair NGC 4532/DDO 137, detected as part of the Arecibo Legacy Fast ALFA (ALFALFA) Survey. The feature is the longest and most massive H I tail structure so far found in the Virgo Cluster and, at 1.8 Mpc from M87, the most distant from the main concentration of the intracluster medium. The structure is spatially and spectrally separated into two ridges and is defined by diffuse emission and discrete clumps of mass (2.5–6.8) × 107 M☉. All emission is blueshifted with …
Structure Formation Inside Triaxial Dark Matter Halos: Galactic Disks, Bulges, And Bars, Clayton Heller, Isaac Shlosman, Evangelie Athanassoula
Structure Formation Inside Triaxial Dark Matter Halos: Galactic Disks, Bulges, And Bars, Clayton Heller, Isaac Shlosman, Evangelie Athanassoula
Department of Physics and Astronomy Faculty Publications
We investigate formation and evolution of galactic disks immersed in assembling live DM halos. Models have been evolved from cosmological initial conditions and represent the collapse of an isolated density perturbation. The baryons include gas participating in star formation (SF) and stars with the energy feedback onto the ISM. We find that (1) the triaxial halo figure tumbling is insignificant and the angular momentum (J) is channeled into the internal circulation, while the baryonic collapse is stopped by the centrifugal barrier; (2) density response of the (disk) baryons is out of phase with DM, thus washing out the …
Evolution Of Stellar Bars In Live Axisymmetric Halos: Recurrent Buckling And Secular Growth, Inma Martinez-Valpuesta, Isaac Shlosman, Clayton Heller
Evolution Of Stellar Bars In Live Axisymmetric Halos: Recurrent Buckling And Secular Growth, Inma Martinez-Valpuesta, Isaac Shlosman, Clayton Heller
Department of Physics and Astronomy Faculty Publications
Evolution of stellar bars in disk galaxies is accompanied by dynamical instabilities and secular changes. Following the vertical buckling instability, the bars are known to weaken dramatically and develop a pronounced boxy/ peanut shape when observed edge-on. Using high-resolution N-body simulations of stellar disks embedded in live axisymmetric dark matter halos, we have investigated the long-term changes in the bar morphology, specifically the evolution of the bar size, its vertical structure, and the exchange of angular momentum. We find that following the initial buckling, the bar resumes its growth from deep inside the corotation radius and follows the ultraharmonic resonance …