Related papers: Stringent constraints on fundamental constant evol…
Understanding physical mechanisms relies on the accurate determination of fundamental constants, although inherent limitations in experimental techniques introduce uncertainties into these measurements. This paper explores the uncertainties…
We present a study of the [OIII]5007/[OII]3727 (O32) ratios of star-forming galaxies drawn from MUSE data spanning a redshift range 0.28<z<0.85. Recently discovered Lyman continuum (LyC) emitters have extremely high oxygen line ratios:…
We report a new constraint on the variation of the fine-structure constant based on the analysis of 15 Si IV doublets selected from a ESO-UVES sample. We find \Delta\alpha/\alpha = (+0.15+/-0.43) x 10^-5 over a redshift range of 1.59< z <…
Star-forming galaxies at high redshifts are the ideal targets to probe the hypothetical variation of the fine-structure constant alpha over cosmological time scales. We propose a modification of the alkali doublets method which allows us to…
We present results from the largest contiguous narrow-band survey in the near-infrared. We have used WIRCam/CFHT and the lowOH2 filter (1.187$\pm$0.005 $\mu$m) to survey ~10 deg$^2$ of contiguous extragalactic sky in the SA22 field. A total…
Astrophysical tests of the stability of dimensionless fundamental couplings, such as the fine-structure constant $\alpha$, are an area of much increased recent activity, following some indications of possible spacetime variations at the few…
We report precise measurements of ground-state, $\lambda$-doublet microwave transitions in the hydroxyl radical molecule (OH). Utilizing slow, cold molecules produced by a Stark decelerator we have improved over the precision of the…
We used Arecibo Observatory and the Green Bank Telescope to observe OH in twelve early-type galaxies with known reservoirs of dense gas. We present three new detections of OH in absorption in the 1667 MHz line. One objective of our survey…
We investigate the properties of $\sim7000$ narrow-band selected galaxies with strong H$\beta+$[OIII] and [OII] nebular emission lines from the High-$z$ Emission Line Survey (HiZELS) between $z \sim 0.8 - 5.0$. Our sample covers a wide…
We critically analyze the Bell et al. findings on "anomalous" widths of high-order Hydrogen radio recombination lines in the Orion Nebula at 6 GHz. We review their method of modified frequency switching and show that the way this method is…
The formation of the cosmic microwave background radiation (CMBR) provides a very powerful probe of the early universe at the epoch of recombination. Specifically, it is possible to constrain the variation of fundamental physical constants…
Development of fundamental physics relies on the constancy of various fundamental quantities such as the fine structure constant. Detecting or constraining the possible time variations of these fundamental physical quantities is an…
[Abridged] Observations of molecular gas at all redshifts are critical for measuring the cosmic evolution in molecular gas density and understanding the star-formation history of the Universe. The 12CO molecule (J=1-0 transition = 115.27…
The redshift-dependent fraction of color-selected galaxies revealing Lyman alpha emission has become the most valuable constraint on the evolving neutrality of the early intergalactic medium. However, in addition to resonant scattering by…
We report the detection of OH satellite line masers at 1720 MHz and 1612 MHz from the nuclear region of the starburst galaxy M82. The observations were aimed at detecting 1720 MHz maser emission from the known radio emitting SNR in the…
Radiative transfer calculations have predicted intensity enhancements for optically thick emission lines, as opposed to the normal intensity reductions, for astrophysical plasmas under certain conditions. In particular, the results are…
The neutral oxygen resonance 1302A line can, if the optical depth is sufficiently high, de-excite by an intercombination transition at 1641A to a metastable state. This has been noted in a number of previous studies but never systematically…
We report Karl G. Jansky Very Large Array (VLA) and Atacama Large Millimeter Array (ALMA) spectroscopy in the redshifted molecular oxygen (O$_2$) 56.265~GHz and 424.763~GHz transitions from the $z=0.88582$ gravitational lens towards…
We present a new constraint on the Hubble constant $H_0$ using a sample of well-localized gravitational wave (GW) events detected during the first three LIGO/Virgo observing runs as dark standard sirens. In the case of dark standard sirens,…
We show how the distances to binary black holes measured in gravitational wave observations with ground-based interferometers can be used to constrain the redshift-distance relation and, thereby, measure the Hubble constant ($H_0$).…