83 research outputs found
Stratospheric Ballooning With SPIDER and BIT
No full textStratospheric ballooning is an important platform for astrophysics and cosmology. This work presents the development of Spider, a CMB polarimeter, and BIT, a visible light and near-UV imager, both of which are balloon experiments. Both experiments require gondolas and pointing systems to track or scan on the sky, and their development is an important area of research in the field.
Spider aims to observe the relics of inflation by constraining the tensor to scalar ratio, r. It flew an initial flight in 2014-15 and the data analysis is presented here. This work includes the development of the Spider noise model which is an important component of any CMB analysis. Development work on the second Spider gondola is also presented, preparing it for a second Antarctic campaign in the near future.
BIT is attempting to constrain Ω_m , the energy density of matter and σ_8 , the scale size of early universe fluctuations, through the use of weak lensing. Although no weak lensing data has been obtained yet, this thesis presents the development of the instrument from its earliest stages through its two successful test flights. Specific emphasis is given to the development of the star camera subsystem, which was integral to the success of the project.Ph.D.2020-07-21 00:00:0
Observing Exoplanets in the Near-Infrared from a High Altitude Balloon Platform
No full textAlthough there exists a large sample of known exoplanets, little data exists that can be used to study their global atmospheric properties. This deficiency can be addressed by performing phase-resolved spectroscopy - continuous spectroscopic observations of a planet's entire orbit about its host star - of transiting exoplanets. Planets with characteristics suitable for atmospheric characterization have orbits of several days, thus phase curve observations are highly resource intensive, especially for shared use facilities. In this work, we show that an infrared spectrograph operating from a high altitude balloon platform can perform phase-resolved spectroscopy of hot Jupiter-type exoplanets with performance comparable to a space-based telescope. Using the EXoplanet Climate Infrared TElescope (EXCITE) experiment as an example, we quantify the impact of the most important systematic effects that we expect to encounter from a balloon platform. We show an instrument like EXCITE will have the stability and sensitivity to significantly advance our understanding of exoplanet atmospheres. Such an instrument will both complement and serve as a critical bridge between current and future space-based near-infrared spectroscopic instruments
Design and Optimization of a 1.5m Telescope Balloon Borne Gondola
No full textGigaBIT is the successor of the Balloon-Borne Imaging Testbed (SuperBIT), a 1.5m telescope that operates in the stratosphere. The GigaBIT gondola must support a telescope almost double the size of SuperBIT while still adhering to the mass restrictionset forth by its predecessor as it will be launched with the same balloon. This presents the challenge of designing a lightweight gondola, strong enough to survive the necessary structural safety requirements and rigid enough to allow for sub-arcsecond
pointing. This thesis explores the design process and development of the gondola. This was done using topological optimization to determine the optimal structural geometry of the gondola’s frames. From there, a design was produced, analyzed and
amended rigorously following static analysis results to adhere to the mandatory design specifications set forth by the Gondola Structural Design Requirements. This design represents a foundation for future balloon-borne astronomy.M.A.S
In Search of an Imprint of Magnetization in the Balloon-borne Observations of the Polarized Dust Emission from Molecular Clouds
No full textThe observation of the polarization of thermal emission from dust grains is a key method in the study of the role of the magnetic fields in the star formation process. This dissertation introduces BLASTPol, a submillimeter telescope for polarization designed for mapping dust polarization in scales ranging from pre-stellar cores to sections of molecular clouds and the Histogram of Relative Orientations (HRO), a new statistical tool for the analysis of the polarization maps.
The observations of BLASTPol were possible thanks to a novel light-weight carbon fiber sunshield structure and the detailed thermal modeling of the balloon-borne platform. The carbon fiber structure is based on the construction technique developed for the Spider gondola which integrates detailed Finite Element Analysis with the use of composite materials
and adhesive joints. The thermal model uses 3D Computer Assisted Design allowing unprecedented control of the sun avoidance limits and detailed modeling of the gondola components.
BLASTPol made observations of the Lupus I and Vela C molecular clouds, the Carina Nebula, and the Puppis Cloud Complex in two balloon-borne flights over Antarctica in 2010 and 2012. The construction of polarization maps from the BLASTPol10 observations was affected by multiple pathologies in the data. However, the preliminary maps indicate the need of a
statistical tool which allows relating these observations to magnetohydrodynamics (MHD) simulations motivating the development of HRO. Most of the problems in the BLASTPol10 data were successfully addressed in BLASTPol12 and the construction of polarization maps of the observed regions is currently in progress.
The HRO is a statistical tool which assesses the relative orientation between the magnetic field and the density structures. This tool was characterized by using simulated molecular clouds with different magnetization indicating that: 1. There is an imprint of the magnetization level in the relative orientation of the projected magnetic field with respect to the column density structure. 2. This imprint of magnetization can be used to complement the current estimates of magnetic field strength provided by the Chandrasekhar-Fermi method. HRO establishes a direct link with MHD simulations providing a common tool for the analysis of polarization maps from BLASTPol.Ph
The EXoplanet Climate Infrared TElescope (EXCITE)
No full textAuthors: Peter C. Nagler, Lee Bernard, Andrea Bocchieri, Nat Butler, Quentin Changeat, Azzurra D'Alessandro, Billy Edwards, John Gamaunt, Qian Gong, John Hartley, Kyle Helson, Logan Jensen, Daniel P. Kelly, Kanchita Klangboonkrong, Annalies Kleyheeg, Nikole K. Lewis, Steven Li, Michael Line, Stephen F. Maher, Ryan McClelland, Laddawan R. Miko, Lorenzo V. Mugnai, C. Barth Netterfield, Vivien Parmentier, Enzo Pascale, Jennifer Patience, Tim Rehm, Javier Romualdez, Subhajit Sarkar, Paul A. Scowen, Gregory S. Tucker, Augustyn Waczynski, Ingo WaldmannSPIE Astronomical Telescopes + Instrumentation, 2022, Montréal,
Québec, CanadaThe EXoplanet Climate Infrared TElescope (EXCITE) is a 0.5 meter near-infrared spectrograph that will fly
from a high altitude balloon platform. EXCITE is designed to perform phase-resolved spectroscopy – continuous
spectroscopic observations of a planet’s entire orbit about its host star – of transiting hot Jupiter-type exoplanets.
With spectral coverage from 0.8 – 4 um, EXCITE will measure the peak of a target’s spectral energy distribution
and the spectral signatures of many hydrogen and carbon-containing molecules. Phase curve observations are
highly resource intensive, especially for shared-use facilities, and they require exceptional photometric stability
that is difficult to achieve, even from space. In this work, we introduce the EXCITE experiment and explain how
it will solve both these problems. We discuss its sensitivity and stability, then provide an update on its current
status as we work toward a 2024 long duration science flight.This work is supported by NASA award 18-APRA18-0075 selected under NASA Research Announcement
NNH18ZDA001N, Research Opportunities in Space Science – 2018 (ROSES-2018), and in part by the NASA
Rhode Island Space Grant. Work by Kyle Helson is supported by NASA under award number 80GSFC17M0002https://www.spiedigitallibrary.org/conference-proceedings-of-spie/12184/121840V/The-EXoplanet-Climate-Infrared-TElescope-EXCITE/10.1117/12.2629373.ful
BFORE: A CMB balloon payload to measure reionization, neutrino mass, and cosmic inflation
No full textBFORE is a high-altitude ultra-long-duration balloon mission to map the cosmic microwave background (CMB). During a 28-day mid-latitude ight launched from Wanaka, New Zealand, the instrument will map half the sky to improve measurements of the optical depth to reionization tau. This will break parameter degeneracies needed to detect neutrino mass. BFORE will also hunt for the gravitational wave B-mode signal, and map Galactic dust foregrounds. The mission will be the first near-space use of TES/mSQUID multichroic detectors (150/217 GHz and 280/353 GHz bands) with low-power readout electronics
Modeling and characterization of the SPIDER half-wave plate
No full textSPIE Astronomical Telescopes + Instrumentation, 2010, San Diego, California, United StatesAuthors: Sean A. Bryan, Peter A. R. Ade, Mandana Amiri, Steve Benton, Richard Bihary, James J. Bock, J. Richard Bond, Joseph A. Bonetti, H. Cynthia Chiang, Carlo R. Contaldi, Brendan P. Crill, Daniel O'Dea, Olivier Dore, Marzieh Farhang, Jeffrey P. Filippini, Laura Fissel, Natalie Gandilo, Sunil Golwala, Jon E. Gudmundsson, Matthew Hasselfield, Mark Halpern, Kyle R. Helson, Gene Hilton, Warren Holmes, Viktor V. Hristov, Kent D. Irwin, William C. Jones, Chao Lin Kuo, Carrie J. MacTavish, Peter Mason, Tracy Morford, Thomas E. Montroy, C. Barth Netterfield, Alexandra S. Rahlin, Carl D. Reintsema, Daniel Riley, John E. Ruhl, Marcus C. Runyan, Matthew A. Schenker, Jamil Shariff, Juan Diego Soler, Amy Transrud, Rebecca Tucker, Carole Tucker, Anthony TurnerSpider is a balloon-borne array of six telescopes that will observe the Cosmic Microwave Background. The 2624 antenna-coupled bolometers in the instrument will make a polarization map of the CMB with approximately one-half degree resolution at 145 GHz. Polarization modulation is achieved via a cryogenic sapphire half-wave plate (HWP) skyward of the primary optic. We have measured millimeter-wave transmission spectra of the sapphire at room and cryogenic temperatures. The spectra are consistent with our physical optics model, and the data gives excellent measurements of the indices of A-cut sapphire. We have also taken preliminary spectra of the integrated HWP, optical system, and detectors in the prototype Spider receiver. We calculate the variation in response of the HWP between observing the CMB and foreground spectra, and estimate that it should not limit the Spider constraints on inflation.Spider is funded by NASA grant number NNX07AL64G, and is also supported by a generous gift from the Gordon and Betty Moore Foundation. WCJ acknowledges the support of the Alfred P. Sloan Foundation.https://www.spiedigitallibrary.org/conference-proceedings-of-spie/7741/1/Modeling-and-characterization-of-the-SPIDER-half-wave-plate/10.1117/12.857837.shor
The design and development status of the cryogenic receiver for the EXoplanet Climate Infrared TELescope (EXCITE)
No full textAuthors: Tim Rehm, Lee Bernard, Andrea Bocchieri, Nat Butler, Quentin Changeat, Azzurra D'Alessandro, Billy Edwards, John Gamaunt, Qian Gong, John Hartley, Kyle Helson, Logan Jensen, Daniel P. Kelly, Kanchita Klangboonkrong, Annalies Kleyheeg, Nikole Lewis, Steven Li, Michael Line, Stephen F. Maher, Ryan McClelland, Laddawan R. Miko, Lorenzo Mugnai, Peter Nagler, C. Barth Netterfield, Vivien Parmentier, Enzo Pascale, Jennifer Patience, Javier Romualdez, Subhajit Sarkar, Paul A. Scowen, Gregory S. Tucker, Augustyn Waczynski, Ingo WaldmannSPIE Astronomical Telescopes + Instrumentation, 2022, Montréal,
Québec, CanadaThe EXoplanet Climate Infrared TElescope (EXCITE) is an instrument dedicated to measuring spectroscopic phase curves of extrasolar giant planets. EXCITE will carry a moderate resolution near-infrared spectrograph and will fly on a long duration balloon mission. We give an overview of the mechanical and thermal design and development status of the EXCITE cryogenic receiver. Active cooling for the EXCITE cryostat is provided by two linear pulse-tube cryocoolers. We discuss cryocooler thermal performance, integration of the spectrometer and detector, and the mounting scheme that attaches the cryostat to the backplate of the telescope. To reject heat power from the cryocoolers, gravity-assisted copper-methanol thermosyphons will maintain cryocooler temperatures within 20 ◦C of ambient temperature during operation. We discuss the results of preliminary thermal modeling of the thermosyphons as well as performance testing of a prototype built for in-lab verification.This work is supported by NASA award 18-APRA18-0075 selected under NASA Research Announcement
NNH18ZDA001N, Research Opportunities in Space Science – 2018 (ROSES-2018), and in part by the NASA
Rhode Island Space Grant. Work by Kyle Helson is supported by NASA under award number 80GSFC17M0002.https://www.spiedigitallibrary.org/conference-proceedings-of-spie/12184/121842I/The-design-and-development-status-of-the-cryogenic-receiver-for/10.1117/12.2629588.full?SSO=1&tab=ArticleLin
Empirical modelling of the BLASTPol achromatic half-wave plate for precision submillimetre polarimetry
No full textA cryogenic achromatic half-wave plate (HWP) for submillimetre astronomical polarimetry
has been designed, manufactured, tested and deployed in the Balloon-borne Large-Aperture
Submillimeter Telescope for Polarimetry (BLASTPol). The design is based on the five-slab
Pancharatnam recipe and itworks in thewavelength range 200–600 μm, making it the broadestband
HWP built to date at (sub)millimetre wavelengths. The frequency behaviour of the HWP
has been fully characterized at room and cryogenic temperatures with incoherent radiation
from a polarizing Fourier transform spectrometer. We develop a novel empirical model, complementary
to the physical and analytical ones available in the literature, that allows us to
recover the HWP Mueller matrix and phase shift as a function of frequency and extrapolated
to 4 K. We show that most of the HWP non-idealities can be modelled by quantifying one
wavelength-dependent parameter, the position of the HWP equivalent axes, which is then readily
implemented in a map-making algorithm. We derive this parameter for a range of spectral
signatures of input astronomical sources relevant to BLASTPol, and provide a benchmark
example of how our method can yield improved accuracy on measurements of the polarization
angle on the sky at submillimetre wavelengths
The SCUBA half-degree extragalactic survey - I. Survey motivation, design and data processing
No full textThe Submillimetre Common-User Bolometer Array ( SCUBA) Half-Degree Extragalactic Survey ( SHADES) is a major new blank-field extragalactic submillimetre (submm) survey currently underway at the James Clerk Maxwell Telescope (JCMT). Ultimately, SHADES aims to cover half a square degree at 450 and 850 mu m to a 4 sigma depth of similar or equal to 8 mJy at 850 mu m. Two fields are being observed, the Subaru/XMM-Newton Deep Field (SXDF) (02(h)18(m) - 05 degrees.) and the Lockman Hole East (10(h)52(m) + 57 degrees). The survey has three main aims: (i) to investigate the population of high-redshift submm galaxies and the cosmic history of massive dust-enshrouded star formation activity; (ii) to investigate the clustering properties of submm-selected galaxies in order to determine whether these objects could be progenitors of present-day massive ellipticals; and (iii) to investigate the fraction of submm-selected sources that harbour active galactic nuclei. To achieve these aims requires that the submm data be combined with cospatial information spanning the radio-to-X-ray frequency range. Accordingly, SHADES has been designed to benefit from ultra-deep radio imaging obtained with the Very Large Array (VLA), deep mid-infrared observations from the Spitzer Space Telescope, submm mapping by the Balloon-borne Large Aperture Submillimetre Telescope ( BLAST), deep near-infrared imaging with the United Kingdom Infrared Telescope, deep optical imaging with the Subaru Telescope and deep X-ray observations with the XMM-Newton observatory. It is expected that the resulting extensive multiwavelength data set will provide complete photometric redshift information accurate to delta(z) 3 sigma at 850 mu m. Although uncorrected for Eddington bias, this source density is more than sufficient for providing enough sources to answer the science goals of SHADES, once half a square degree is observed. A refined reanalysis of the original 8-mJy survey Lockman hole data was carried out in order to evaluate the new data-reduction pipeline. Of the 17 most secure sources in the original sample, 12 have been reconfirmed, including 10 of the 11 for which radio identifications were previously secured
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