Publications (28)
Microwave Observations of Venus with CLASS
Sumit Dahal, Michael K. Brewer, Alex B. Akins +21
We report on the disk-averaged absolute brightness temperatures of Venus measured at four microwave frequency bands with the Cosmology Large Angular Scale Surveyor (CLASS). We meas…
COMAP Early Science: II. Pathfinder Instrument
James W. Lamb, Kieran A. Cleary, David P. Woody +32
Line intensity mapping (LIM) is a new technique for tracing the global properties of galaxies over cosmic time. Detection of the very faint signals from redshifted carbon monoxide…
Four-year Cosmology Large Angular Scale Surveyor (CLASS) Observations: On-sky Receiver Performance at 40, 90, 150, and 220 GHz Frequency Bands
Sumit Dahal, John W. Appel, Rahul Datta +37
The Cosmology Large Angular Scale Surveyor (CLASS) observes the polarized cosmic microwave background (CMB) over the angular scales of 1 90 with the…
Analysis of the distribution of precipitable water vapor in the Chajnantor area
Fernando Cortés, Rodrigo Reeves, Ricardo Bustos
In this work, we present results from a long-term precipitable water vapor (PWV) study in the Chajnantor area, in northern Chile. Data from several instruments located at relevant…
Two-year Cosmology Large Angular Scale Surveyor (CLASS) Observations: A Measurement of Circular Polarization at 40 GHz
Ivan L. Padilla, Joseph R. Eimer, Yunyang Li +32
We report circular polarization measurements from the first two years of observation with the 40 GHz polarimeter of the Cosmology Large Angular Scale Surveyor (CLASS). CLASS is con…
Deep-learning-based prediction of Precipitable Water Vapor in the Chajnantor area
Alison Matus-Bello, Silvia E. Restrepo, Ricardo Bustos +7
Astronomical observations at millimeter and submillimeter wavelengths heavily depend on the amount of Precipitable Water Vapor (PWV) in the atmosphere, directly affecting the sky t…
A Measurement of the Largest-Scale CMB E-mode Polarization with CLASS
Yunyang Li, Joseph Eimer, John Appel +34
We present measurements of large-scale cosmic microwave background (CMB) E-mode polarization from the Cosmology Large Angular Scale Surveyor (CLASS) 90 GHz data. Using 115 det-yr o…
Demographics of black holes at 100 R scales: accretion flows, jets, and shadows
Dhanya G. Nair, Neil M. Nagar, Venkatessh Ramakrishnan +87
Using the Event Horizon Telescope (EHT), the gravitationally lensed rings around the supermassive black holes (SMBHs) in Messier 87 (M87) and Sagittarius A* (Sgr A*) have now been…
CLASS Data Pipeline and Maps for 40 GHz Observations through 2022
Yunyang Li, Joseph Eimer, Keisuke Osumi +33
The Cosmology Large Angular Scale Surveyor (CLASS) is a telescope array that observes the cosmic microwave background over 75\% of the sky from the Atacama Desert, Chile, at freque…
COMAP Early Science: I. Overview
Kieran A. Cleary, Jowita Borowska, Patrick C. Breysse +40
The CO Mapping Array Project (COMAP) aims to use line intensity mapping of carbon monoxide (CO) to trace the distribution and global properties of galaxies over cosmic time, back t…
Contemporaneous VLBA 5 GHz Observations of LAT-Detected Blazars
Justin D. Linford, Gregory B. Taylor, Roger W. Romani +4
The radio properties of blazars detected by the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope have been observed contemporaneously by the Very Long Baseli…
Two-year Cosmology Large Angular Scale Surveyor (CLASS) Observations: 40 GHz Telescope Pointing, Beam Profile, Window Function, and Polarization Performance
Zhilei Xu, Michael K. Brewer, Pedro Fluxá Rojas +33
The Cosmology Large Angular Scale Surveyor (CLASS) is a telescope array that observes the cosmic microwave background (CMB) over 75% of the sky from the Atacama Desert, Chile, at f…
VERITAS discovery of very high energy gamma-ray emission from S3 1227+25 and multiwavelength observations
Atreya Acharyya, Colin Adams, Avery Archer +68
We report the detection of very high energy gamma-ray emission from the blazar S3 1227+25 (VER J1230+253) with the Very Energetic Radiation Imaging Telescope Array System (VERITAS)…
Cosmology Large Angular Scale Surveyor (CLASS): 90 GHz Telescope Pointing, Beam Profile, Window Function, and Polarization Performance
Rahul Datta, Michael K. Brewer, Jullianna Denes Couto +31
The Cosmology Large Angular Scale Surveyor (CLASS) is a telescope array that observes the cosmic microwave background (CMB) over ~75% of the sky from the Atacama Desert, Chile, at…
Variable-delay Polarization Modulators for the CLASS Telescopes
Kathleen Harrington, Joseph Eimer, David T. Chuss +43
The search for inflationary primordial gravitational waves and the measurement of the optical depth to reionization, both through their imprint on the large angular scale correlati…
Radio Variability Studies of Gamma-Ray Blazars with the OVRO 40 m Telescope
Joseph L. Richards, Walter Max-Moerbeck, Vasiliki Pavlidou +6
Since late 2007, we have been monitoring a large sample of known and likely gamma-ray-loud blazars at 15 GHz twice per week with the Owens Valley Radio Observatory (OVRO) 40 m Tele…
Design of the tertiary optical system for the Large Latin American Millimeter Array radio telescope
Emiliano Rasztocky, Matias Rolf Hampel, Rodrigo Reeves +2
Many modern radio telescopes employ an observational strategy that involves maximizing the use of their available spaces (cabins), outfitting them with various receivers at differe…
Two decades of km-resolution satellite-based measurements of the precipitable water vapor above the Atacama Desert
Pablo Gómez Toribio, Tony Mroczkowski, Anna Cabré +3
The Atacama Desert has long been established as an excellent site for submillimeter observations. Yet identifying potentially optimal locations for a new facility within this regio…
Twenty years of PWV measurements in the Chajnantor Area
Fernando Cortés, Katherine Cortés, Rodrigo Reeves +2
Context. Interest in the use of the Chajnantor area for millimeter and submillimeter astronomy is increasing because of its excellent atmospheric conditions. Knowing the general si…
Design and characterization of the Cosmology Large Angular Scale Surveyor (CLASS) 93 GHz focal plane
Sumit Dahal, Aamir Ali, John W. Appel +44
The Cosmology Large Angular Scale Surveyor (CLASS) aims to detect and characterize the primordial B-mode signal and make a sample-variance-limited measurement of the optical depth…
Blazars in the Fermi Era: The OVRO 40-m Telescope Monitoring Program
Joseph L. Richards, Walter Max-Moerbeck, Vasiliki Pavlidou +20
The Large Area Telescope (LAT) aboard the Fermi Gamma-ray Space Telescope provides an unprecedented opportunity to study gamma-ray blazars. To capitalize on this opportunity, begin…
Milliarcsecond Core Size Dependence of the Radio Variability of Blazars
Po Chih Hsu, Jun Yi Koay, Satoki Matsushita +6
Studying the long-term radio variability (timescales of months to years) of blazars enables us to gain a better understanding of the physical structure of these objects on sub-pars…
Venus Observations at 40 and 90 GHz with CLASS
Sumit Dahal, Michael K. Brewer, John W. Appel +30
Using the Cosmology Large Angular Scale Surveyor, we measure the disk-averaged absolute Venus brightness temperature to be 432.3 2.8 K and 355.6 1.3 K in the Q and W fr…
The Cosmic Background Imager 2
Angela C. Taylor, Michael E. Jones, James R. Allison +14
We describe an upgrade to the Cosmic Background Imager instrument to increase its surface brightness sensitivity at small angular scales. The upgrade consisted of replacing the thi…
Two Year Cosmology Large Angular Scale Surveyor (CLASS) Observations: Long Timescale Stability Achieved with a Front-End Variable-delay Polarization Modulator at 40 GHz
Kathleen Harrington, Rahul Datta, Keisuke Osumi +33
The Cosmology Large Angular Scale Surveyor (CLASS) is a four-telescope array observing the largest angular scales () of the cosmic microwave backgroun…
Technology developments for a scalable heterodyne MMIC array at W-band
Matthew Sieth, Sarah Church, Judy M. Lau +13
We report on the development of W-band (75-110 GHz) heterodyne receiver technology for large-format astronomical arrays. The receiver system is designed to be both mass-producible,…
Two-year Cosmology Large Angular Scale Surveyor (CLASS) Observations: A First Detection of Atmospheric Circular Polarization at Q Band
Matthew A. Petroff, Joseph R. Eimer, Kathleen Harrington +27
The Earth's magnetic field induces Zeeman splitting of the magnetic dipole transitions of molecular oxygen in the atmosphere, which produces polarized emission in the millimeter-wa…
The Cosmology Large Angular Scale Surveyor Receiver Design
Jeffrey Iuliano, Joseph Eimer, Lucas Parker +42
The Cosmology Large Angular Scale Surveyor consists of four instruments performing a CMB polarization survey. Currently, the 40 GHz and first 90 GHz instruments are deployed and ob…