Search Publications
A study of the circumgalactic medium at z ∼ 0.6 using damped Lyman α galaxies
Turnshek, David A.; Rao, Sandhya M.; Kulkarni, Varsha P. +6 more
We present the study of a sample of nine quasi-stellar object fields, with damped Lyman α (DLA) or sub-DLA systems at z ∼ 0.6, observed with the X-Shooter spectrograph at the Very Large Telescope. By suitably positioning the X-Shooter slit based on high spatial resolution images of Hubble Space Telescope/Advanced Camera for Surveys we are able to …
Acceleration of the universe: a reconstruction of the effective equation of state
Mukherjee, Ankan
This work is based upon a parametric reconstruction of the effective or total equation of state in a model for the Universe with accelerated expansion. The constraints on the model parameters are obtained by maximum-likelihood analysis using the supernova distance modulus data, observational Hubble data, baryon acoustic oscillation data and cosmic…
Impacts of spontaneous hot flow anomalies on the magnetosheath and magnetopause
Berchem, J.; Zhang, H.; Omidi, N. +1 more
Spacecraft observations and global hybrid (kinetic ions and fluid electrons) simulations have demonstrated that ion dissipation processes at the quasi-parallel bow shock are associated with the formation of structures called spontaneous hot flow anomalies (SHFAs). Previous simulations and recent spacecraft observations have also established that S…
Caught in the Act: Gas and Stellar Velocity Dispersions in a Fast Quenching Compact Star-Forming Galaxy at z~1.7
Finkelstein, Steven L.; Barro, Guillermo; Pérez-González, Pablo G. +20 more
We present Keck I MOSFIRE spectroscopy in the Y and H bands of GDN-8231, a massive, compact, star-forming galaxy at a redshift of z ∼ 1.7. Its spectrum reveals both Hα and [N II] emission lines and strong Balmer absorption lines. The Hα and Spitzer MIPS 24 µm fluxes are both weak, thus indicating a low star-formation rate of SFR ≲ 5{--}10 {M…
AGN feedback in the nucleus of M 51
Meidt, S. E.; Schinnerer, E.; Leroy, A. K. +10 more
AGN feedback is invoked as one of the most relevant mechanisms that shape the evolution of galaxies. Our goal is to understand the interplay between AGN feedback and the interstellar medium in M 51, a nearby spiral galaxy with a modest AGN and a kpc-scale radio jet expanding through the disc of the galaxy. For this purpose, we combine molecular ga…
Search for 511 keV emission in satellite galaxies of the Milky Way with INTEGRAL/SPI
Vincent, Aaron C.; Diehl, Roland; Siegert, Thomas +3 more
Context. The positron (e+) annihilation γ-ray signal in the Milky Way (MW) shows a puzzling morphology: a very bright bulge and a very low surface-brightness disk. A coherent explanation of the e+ origin, propagation through the Galaxy and subsequent annihilation in the interstellar medium has not yet been found. Tentative ex…
Sizes, colour gradients and resolved stellar mass distributions for the massive cluster galaxies in XMMUJ2235-2557 at z = 1.39
Bender, Ralf; Mendel, J. Trevor; Cappellari, Michele +13 more
We analyse the sizes, colour gradients and resolved stellar mass distributions for 36 massive and passive galaxies in the cluster XMMUJ2235-2557 at z = 1.39 using optical and near-infrared Hubble Space Telescope (HST) imaging. We derive light-weighted Sérsic fits in five HST bands (I775, z850, Y105, J125…
The outburst decay of the low magnetic field magnetar SWIFT J1822.3-1606: phase-resolved analysis and evidence for a variable cyclotron feature
Mereghetti, Sandro; Esposito, Paolo; Turolla, Roberto +12 more
We study the timing and spectral properties of the low-magnetic field, transient magnetar SWIFT J1822.3-1606 as it approached quiescence. We coherently phase-connect the observations over a time-span of ∼500 d since the discovery of SWIFT J1822.3-1606 following the Swift-Burst Alert Telescope (BAT) trigger on 2011 July 14, and carried out a detail…
The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters. VII. Implications from the Nearly Universal Nature of Horizontal Branch Discontinuities
Dalessandro, E.; Salaris, M.; Anderson, J. +14 more
The UV-initiative Hubble Space Telescope Treasury survey of Galactic globular clusters provides a new window into the phenomena that shape the morphological features of the horizontal branch (HB). Using this large and homogeneous catalog of UV and blue photometry, we demonstrate that the HB exhibits discontinuities that are remarkably consistent i…
High-velocity extended molecular outflow in the star-formation dominated luminous infrared galaxy ESO 320-G030
Colina, L.; Villar-Martín, M.; Planesas, P. +9 more
We analyze new high spatial resolution (~60 pc) ALMA CO(2-1) observations of the isolated luminous infrared galaxy ESO 320-G030 (d = 48 Mpc) in combination with ancillary Hubble Space Telescope optical and near infrared (IR) imaging, as well as VLT/SINFONI near-IR integral field spectroscopy. We detect a high-velocity (~450 km s-1) spat…