Search Publications
Planet Hunters TESS III: two transiting planets around the bright G dwarf HD 152843
Aigrain, S.; Stassun, K.; Barragán, O. +37 more
We report on the discovery and validation of a two-planet system around a bright (V = 8.85 mag) early G dwarf (1.43 R⊙, 1.15 M⊙, TOI 2319) using data from NASA's Transiting Exoplanet Survey Satellite (TESS). Three transit events from two planets were detected by citizen scientists in the month-long TESS light curve (sector 25…
Constraints on planets in nearby young moving groups detectable by high-contrast imaging and Gaia astrometry
Federrath, C.; Ireland, M. J.; Wallace, A. L.
The formation of giant planets can be studied through direct imaging by observing planets both during and after formation. Giant planets are expected to form either by core accretion, which is typically associated with low initial entropy (cold-start models) or by gravitational instability, associated with high initial entropy of the gas (hot-star…
The magnetic field in the dense photodissociation region of DR 21
Menten, Karl M.; Jacob, Arshia M.; Pillai, Thushara G. S. +3 more
Measuring interstellar magnetic fields is extremely important for understanding their role in different evolutionary stages of interstellar clouds and star formation. However, detecting the weak field is observationally challenging. We present measurements of the Zeeman effect in the 1665 and 1667 MHz (18 cm) lines of the hydroxyl radical (OH) lin…
Azimuthal propagation of star formation in nearby spiral galaxies: NGC 628, NGC 3726, and NGC 6946
Gusev, A. S.; Sakhibov, F.; Hemmerich, C.
Star formation induced by a spiral shock wave, which in turn is generated by a spiral density wave, produces an azimuthal age gradient across the spiral arm, which has opposite signs on either side of the corotational resonance. An analysis of the spatial separation between young star clusters and nearby H II regions has made it possible to determ…
Discovery of extremely low-metallicity circumgalactic gas at z = 0.5 towards Q0454-220
Charlton, Jane C.; Kacprzak, Glenn G.; Churchill, Christopher W. +3 more
We have obtained new observations of the absorption system at zabs = 0.48 towards QSO Q0454-220, which we use to constrain its chemical and physical conditions. The system features metal-enriched gas and previously unknown low-metallicity gas detected ${\sim} 200 \, \mathrm{km \, s^{-1}}$ blueward of the metal-enriched gas. The low-meta…
A low-frequency radio halo survey of the South Pole Telescope SZ-selected clusters with the GMRT
Rahaman, Majidul; Raja, Ramij; Datta, Abhirup +3 more
The presence of non-thermal electrons and large-scale magnetic fields in the intracluster medium is known through the detection of megaparsec (Mpc) scale diffuse radio synchrotron emission. Although a significant amount of progress in finding new diffuse radio sources has happened in the last decade, most of the investigation has been constrained …
A partial Lyman limit system tracing intragroup gas at z ≈ 0.8 towards HE 1003 + 0149
Charlton, Jane C.; Johnson, Sean D.; Sameer +6 more
We present analysis of the galaxy environment and physical properties of a partial Lyman limit system at z = 0.83718 with H I and metal-line components closely separated in redshift space (|Δv| ≈ 400 km s-1) towards the background quasar HE 1003 + 0149. The HST/COS far-ultraviolet spectrum provides coverage of lines of oxygen ions from …
A search for optical laser emission from Proxima Centauri
Marcy, G. W.
A search for laser light from Proxima Centauri was performed, including 107 high-resolution, optical spectra obtained between 2004 and 2019 with the HARPS spectrometer. The search for laser light involved rejecting sharp peaks in the spectrum from stellar flares, fluorescent city lights, and elementary particles that directly hit the CCD detector.…
Chandra and HST studies of six millisecond pulsars in the globular cluster M13
Zhao, Jiaqi; Heinke, Craig O.; Zhao, Yue
We analyse 55 ks of Chandra X-ray observations of the Galactic globular cluster (GC) M13. Using the latest radio timing positions of six known millisecond pulsars (MSPs) in M13 from Wang et al. (2020), we detect confident X-ray counterparts to five of the six MSPs at X-ray luminosities of LX(0.3-8 keV)∼3 × 1030-1031
The MOSDEF survey: the dependence of H α-to-UV SFR ratios on SFR and size at z 2
Siana, Brian; Shapley, Alice E.; Reddy, Naveen A. +12 more
We perform an aperture-matched analysis of dust-corrected H α and UV star formation rates (SFRs) using 303 star-forming galaxies with spectroscopic redshifts 1.36 < zspec < 2.66 from the MOSFIRE Deep Evolution Field survey. By combining H α and H β emission line measurements with multiwaveband resolved Cosmic Assembly Near-infrare…