Related papers: On the Detectability of the Hydrogen 3-cm Fine Str…
We have undertaken a survey for HI 21-cm absorption within the host galaxies of z ~ 1.2 - 1.5 radio sources, in the search of the cool neutral gas currently "missing" at z > 1. This deficit is believed to be due to the optical selection of…
We propose observations of the molecular gas distribution during the era of reionization. At $z \sim $ 6 to 8, $^{12}$CO$(J=1-0)$ line intensity results in a mean brightness temperature of about 0.5 $\mu$K with rms fluctuations of 0.1…
We present the first systematic investigation of the [NeV] (14um/24um) and [SIII] (18um/33um) infrared line flux ratios, traditionally used to estimate the density of the ionized gas, in a sample of 41 Type 1 and Type 2 active galactic…
We study the prospects for extracting detailed statistical properties of the neutral Hydrogen distribution during the era of reionization using the brightness temperature fluctuations from redshifted 21 cm line emission. Detection of this…
We report the detection of luminous CO(3-2) line emission in the halo of the z=2.6 radio galaxy (HzRG) TXS0828+193, which has no detected counterpart at optical to mid-infrared wavelengths implying a stellar mass < few x10^9 M_sun and…
We report the detection of strong absorption and weak emission features in the 4--27 micron Spitzer-IRS spectrum of the distant ultraluminous infrared galaxy (ULIRG) IRAS F00183--7111 (z=0.327). The absorption features of CO2 and CO gas,…
Old isolated accreting neutron stars may show up among unidentified soft X--ray sources detected by the ROSAT All Sky Survey. We argue that the chances of identification are greater for ONSs located in the closest overdense regions of the…
We present a deep near-infrared spectrum of the Orion Bar Photodissociation Region (PDR) taken with the Immersion Grating INfrared Spectrometer (IGRINS) on the 2.7 m telescope at the McDonald Observatory. IGRINS has high spectral resolution…
We use synthetic sightlines drawn through snapshots of the Technicolor Dawn simulations to explore how the statistics of neutral oxygen OI absorbers respond to hydrogen reionization. The ionization state of the circumgalactic medium (CGM)…
The relatively large Thomson optical depth, tau_e, inferred recently from the WMAP observations suggests that the Universe was reionized in a more complex manner than previously believed. However, the value of tau_e provides only an…
We report the detection of the 1_{10}-1_{11} ground state transition of ortho-H_2D^+ at 372.421 GHz in emission from the young stellar object NGC 1333 IRAS 4A. Detailed excitation models with a power-law temperature and density structure…
Nearby interstellar clouds with high (|v| >/= 10 km/s) random velocities although easily detected in NaI and CaII lines have hitherto not been detected (in emission or absorption) in the HI 21cm line. We describe here deep Giant Metrewave…
We use numerical simulations of hydrogen reionization by stellar sources in the context of LCDM cosmogonies to investigate the 21 (1+z) cm radio signal expected from the diffuse intergalactic medium (IGM) prior to the epoch of reionization…
One of the key goals of observing neutron stars is to infer the equation of state (EoS) of the cold, ultradense matter in their interiors. We present here a Bayesian statistical method of inferring the pressures at five fixed densities,…
We present mid-infrared spectra and photometry from the Infrared Spectrograph on the Spitzer Space Telescope for 51 OH megamasers (OHMs), along with 15 galaxies confirmed to have no megamaser emission above L_OH = 10^2.3 L_sun. The majority…
Galaxy and occupies perhaps a quarter of the volume of the Galactic disk. Decoding the spectrum of the Galactic diffuse ionizing field is of fundamental interest. This can be done via direct measurements of ionization fractions of various…
We report the discovery of a further line of sight allowing detection of HeII Ly alpha absorption by the intergalactic medium. A HST/STIS survey of 32 bright z ~ 3 quasars selected from the Hamburg Quasar Surveys yielded one detection…
The Epoch of Reionization (EoR) is a key period of cosmological history in which the intergalactic medium (IGM) underwent a major phase change from being neutral to almost completely ionized. Gamma-ray bursts (GRBs) are luminous and unique…
Context. The Fred Young Submillimeter Telescope (FYST) line intensity mapping (LIM) survey will measure the power spectrum (PS) of the singly ionized carbon 158 $\rm \mu$m fine-structure line, [CII], to trace the appearance of the first…
Despite much searching, redshifted decimetre and millimetre-band absorption by molecular gas remains very rare, limited to just six systems at z > 0.05. Detection of these transitions can yield precise diagnostics of the conditions of the…