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In order to understand the role of magnetic fields in the process of star formation, we require detailed observations of field morphology on scales ranging from clouds to cores. However, ground based millimetre/submillimetre polarimetry is usually limited to small maps of relatively dense regions. BLASTPol, the Balloon-borne Large Aperture Sub-mm Telescope for Polarimetry, maps linear polarization at 250, 350 and 500 microns with arcminute resolution. Its high sensitivity and resolving power allow BLASTPol to bridge the gap in spatial scales between the polarization capabilities of Planck and ALMA.I will present early results from the second flight of BLASTPol, focusing on our observations of the Vela C molecular cloud, an early stage intermediate mass star forming region (d~700 pc). With thousands of independent measurements of magnetic field direction, this is the most detailed sub-mm polarization map of a GMC to date. The field we observe in this elongated cloud exhibits a coherent, large-scale ~ 90 degree bend between its high latitude and low latitude edges. I will discuss what we can learn about star formation in Vela C from the combination of BLASTPol polarization maps and velocity information from molecular line observations, and what the variation of polarization strength across the cloud can tell us about dust grain alignment in GMCs.

Polarized thermal emission from dust grains can be used to trace magnetic fields in molecular clouds and the ISM. The Balloon-borne Large Aperture Submillimeter Telescope for Polarimetry (BLASTPol) flew from Antarctica in 2010 and 2012 and has produced degree scale polarization maps of multiple nearby molecular clouds with arcminute resolution. The success of BLASTPol has motivated a next-generation instrument, BLAST-TNG, with additional resolution and sensitivity to fully understand the role magnetic fields play in the early stages of the star formation process. BLAST-TNG will use an array of ~1500 linear polarization sensitive pixels populated with Microwave Kinetic Inductance Detectors (MKIDs) combined with a 2.5 m diameter carbon fiber primary mirror to make diffraction limited observations at 250, 350, and 500 microns. With 16 times the mapping speed of BLASTPol, sub-arcminute resolution, and a longer flight time, BLAST-TNG will be able to examine nearby molecular clouds and the diffuse galactic dust polarization spectrum in unprecedented detail. Additionally, the instrument will be in a unique position to link the all-sky, five arcminute resolution, dust polarization maps of Planck with the high resolution, but small area, polarization maps from ALMA allowing us to trace magnetic fields from protostellar cores out to the surrounding molecular clouds and ISM. BLAST-TNG is scheduled to fly from Antarctica in 2016 for 28 days and will be the first balloon-borne telescope to offer a quarter of the flight for "shared risk" observing by the community.

The BLAST Observatory is a proposed super-pressure balloon-borne polarimeter designed for a future ultra- long duration balloon campaign from Wanaka, New Zealand. To maximize scientific output while staying within the stringent super-pressure weight envelope, BLAST will feature new 1.8m off-axis optical system contained within a lightweight monocoque structure gondola. The payload will incorporate a 300 L 4He cryogenic receiver which will cool 8,274 microwave kinetic inductance detectors (MKIDs) to 100mK through the use of an adiabatic demagnetization refrigerator (ADR) in combination with a 3He sorption refrigerator all backed by a liquid helium pumped pot operating at 2 K. The detector readout utilizes a new Xilinx RFSOC-based system which will run the next-generation of the BLAST-TNG KIDPy software. With this instrument we aim to answer outstanding questions about dust dynamics as well as provide community access to the polarized submillimeter sky made possible by high-altitude observing unrestricted by atmospheric transmission. The BLAST Observatory is designed for a minimum 31-day flight of which 70% will be dedicated to observations for BLAST scientific goals and the remaining 30% will be open to proposals from the wider astronomical community through a shared-risk proposals program....

The Next Generation Balloon-borne Large Aperture Submillimeter Telescope (BLAST-TNG) is an experiment designed to map magnetic fields in molecular clouds in order to study their role in the star formation process. The telescope will be launched aboard a high-altitude balloon in December 2016 for a 4-week flight from McMurdo station in Antarctica. BLAST-TNG will measure the polarization of submillimeter thermal emission from magnetically aligned interstellar dust grains, using large format arrays of kinetic inductance detectors operating in three bands centered at 250, 350, and 500 microns, with sub-arcminute angular resolution. The optical system includes an achromatic Half Wave Plate (HWP), mounted in a Half Wave Plate rotator (HWPr). The HWP and HWPr will operate at 4 K temperature to reduce thermal noise in our measurements, so it was crucial to account for the effects of thermal contraction at low temperature in the HWPr design. It was also equally important for the design to meet torque requirements while minimizing the power from friction and conduction dissipated at the 4 K stage. We also discuss our plan for cold testing the HWPr using a repurposed cryostat with a Silicon Diode thermometer read out by an EDAS-CE Ethernet data acquisition system.

Polarized thermal emission from dust grains can be used to trace magnetic fields in molecular clouds and the ISM. The Balloon-borne Large Aperture Submillimeter Telescope for Polarimetry (BLASTPol) flew from Antarctica in 2010 and 2012 and has produced degree scale polarization maps of multiple nearby molecular clouds with arcminute resolution. The success of BLASTPol has motivated a next-generation instrument, BLAST-TNG, with additional resolution and sensitivity to fully understand the role magnetic fields play in the early stages of the star formation process. BLAST-TNG will use an array of ~1500 linear polarization sensitive pixels populated with Microwave Kinetic Inductance Detectors (MKIDs) combined with a 2.5 m diameter carbon fiber primary mirror to make diffraction limited observations at 250, 350, and 500 microns. With 16 times the mapping speed of BLASTPol, sub-arcminute resolution, and a longer flight time, BLAST-TNG will be able to examine nearby molecular clouds and the diffuse galactic dust polarization spectrum in unprecedented detail. Additionally, the instrument will be in a unique position to link the all-sky, five arcminute resolution, dust polarization maps of Planck with the high resolution, but small area, polarization maps from ALMA allowing us to trace magnetic fields from protostellar cores out to the surrounding molecular clouds and ISM. BLAST-TNG is scheduled to fly from Antarctica in 2016 for 28 days and will be the first balloon-borne telescope to offer a quarter of the flight for "shared risk" observing by the community.

The Next Generation Balloon-Borne Large Aperture Submillimeter Telescope (BLAST-TNG) was a unique instrument for characterizing the polarized submillimeter sky at high-angular resolution. BLAST-TNG flew from the Long Duration Balloon Facility in Antarctica in January 2020. Despite the short flight duration, the instrument worked very well and is providing significant information about each subsystem that will be invaluable for future balloon missions. In this contribution, we discuss the performance of telescope and gondola....

TolTEC is an imaging polarimeter that will be mounted on the 50m diameter Large Millimeter Telescope (LMT) in Mexico. This camera simultaneously images the focal plane at three wavebands centered at 1.1, 1.4, and 2.0mm. TolTEC combines polarization-sensitive Kinetic Inductance Detectors (KIDs) with the LMT to produce 5-10 arcmin resolution maps of the sky in both total intensity and polarization. The light from the telescope is coupled to the TolTEC instrument using three room temperature mirrors. Before entering the cryostat, the light passes through a rapid-spinning achromatic half-wave plate, and once inside it passes through a 1 K Lyot stop that controls the telescope illumination. Inside the cryostat, a series of aluminum mirrors, silicon lenses, and dichroic filters split the light into three wavelength bands and direct each band to a different detector array. We will describe the design, and performance of the optics before installation at the telescope....

In order to understand the role of magnetic fields in the process of star formation, we require detailed observations of field morphology on scales ranging from clouds to cores. However, ground based millimetre/submillimetre polarimetry is usually limited to small maps of relatively dense regions. BLASTPol, the Balloon-borne Large Aperture Sub-mm Telescope for Polarimetry, maps linear polarization at 250, 350 and 500 microns with arcminute resolution. Its high sensitivity and resolving power allow BLASTPol to bridge the gap in spatial scales between the polarization capabilities of Planck and ALMA.I will present early results from the second flight of BLASTPol, focusing on our observations of the Vela C molecular cloud, an early stage intermediate mass star forming region (d~700 pc). With thousands of independent measurements of magnetic field direction, this is the most detailed sub-mm polarization map of a GMC to date. The field we observe in this elongated cloud exhibits a coherent, large-scale ~ 90 degree bend between its high latitude and low latitude edges. I will discuss what we can learn about star formation in Vela C from the combination of BLASTPol polarization maps and velocity information from molecular line observations, and what the variation of polarization strength across the cloud can tell us about dust grain alignment in GMCs.

The Next Generation Balloon-borne Large Aperture Submillimeter Telescope (BLAST-TNG) is a submillimeter polarimeter designed to map interstellar dust and galactic foregrounds at 250, 350, and 500 microns during a 24-day Antarctic flight. The BLAST-TNG detector arrays are comprised of 918, 469, and 272 MKID pixels, respectively. The pixels are formed from two orthogonally oriented, crossed, linear-polarization sensitive MKID antennae. The arrays are cooled to sub 300 mK temperatures and stabilized via a closed cycle 3He sorption fridge in combination with a 4He vacuum pot. The detectors are read out through a combination of the second-generation Reconfigurable Open Architecture Computing Hardware (ROACH2) and custom RF electronics designed for BLAST-TNG. The firmware and software designed to readout and characterize these detectors was built from scratch by the BLAST team around these detectors, and has been adapted for use by other MKID instruments such as TolTEC and OLIMPO.1 We present an overview of these systems as well as in-depth methodology of the ground-based characterization and the measured in-flight performance....

A key outstanding question in our understanding of star formation is whether magnetic fields provide support against the gravitational collapse of their parent molecular clouds and cores. Direct measurement of magnetic field strength is observationally challenging, however observations of polarized thermal emission from dust grains aligned with respect to the local cloud magnetic field can be used to map out the magnetic field orientation in molecular clouds. Statistical comparisons between these submillimeter polarization maps and three-dimensional numerical simulations of magnetized star-forming clouds provide a promising method for constraining magnetic field strength. We present early results from a BLASTPol study of the nearby giant molecular cloud (GMC) Vela C, using data collected during a 2012 Antarctic flight. This sensitive balloon-borne polarimeter observed Vela C for 57 hours, yielding the most detailed submillimeter polarization map ever made of a GMC forming high mass stars. We find that most of the structure in p can be modeled by a power-law dependence on two quantities: the hydrogen column density and the local dispersion in magnetic field orientation. Our power-law model for p(N,S) provides new constraints for models of magnetized star-forming clouds and an important first step in the interpretation of the BLASTPol 2012 data set.

TolTEC is a three-band imaging polarimeter for the Large Millimeter Telescope. Simultaneously observing with passbands at 1.1mm, 1.4mm and 2.0mm, TolTEC has diffraction-limited beams with FWHM of 5, 7, and 11 arcsec, respectively. Over the coming decade, TolTEC will perform a combination of PI-led and Open-access Legacy Survey projects. Herein we provide an overview of the instrument and give the first quantitative measures of its performance in the lab prior to shipping to the telescope in 2021.

A key outstanding question in our understanding of star formation is whether magnetic fields provide support against the gravitational collapse of their parent molecular clouds and cores. Direct measurement of magnetic field strength is observationally challenging, however observations of polarized thermal emission from dust grains aligned with respect to the local cloud magnetic field can be used to map out the magnetic field orientation in molecular clouds. Statistical comparisons between these submillimeter polarization maps and three-dimensional numerical simulations of magnetized star-forming clouds provide a promising method for constraining magnetic field strength. We present early results from a BLASTPol study of the nearby giant molecular cloud (GMC) Vela C, using data collected during a 2012 Antarctic flight. This sensitive balloon-borne polarimeter observed Vela C for 57 hours, yielding the most detailed submillimeter polarization map ever made of a GMC forming high mass stars. We find that most of the structure in p can be modeled by a power-law dependence on two quantities: the hydrogen column density and the local dispersion in magnetic field orientation. Our power-law model for p(N,S) provides new constraints for models of magnetized star-forming clouds and an important first step in the interpretation of the BLASTPol 2012 data set.

The Next Generation Balloon-borne Large Aperture Submillimeter Telescope (BLAST-TNG) is an experiment designed to map magnetic fields in molecular clouds in order to study their role in the star formation process. The telescope will be launched aboard a high-altitude balloon in December 2016 for a 4-week flight from McMurdo station in Antarctica. BLAST-TNG will measure the polarization of submillimeter thermal emission from magnetically aligned interstellar dust grains, using large format arrays of kinetic inductance detectors operating in three bands centered at 250, 350, and 500 microns, with sub-arcminute angular resolution. The optical system includes an achromatic Half Wave Plate (HWP), mounted in a Half Wave Plate rotator (HWPr). The HWP and HWPr will operate at 4 K temperature to reduce thermal noise in our measurements, so it was crucial to account for the effects of thermal contraction at low temperature in the HWPr design. It was also equally important for the design to meet torque requirements while minimizing the power from friction and conduction dissipated at the 4 K stage. We also discuss our plan for cold testing the HWPr using a repurposed cryostat with a Silicon Diode thermometer read out by an EDAS-CE Ethernet data acquisition system.

An ambient-temperature Continuously Rotating Half-Wave Plate (CRHWP) modulates the input polarization signal thereby enabling removal of low-frequency (1/f) noise from polarized flux measurements. This 1/f noise arises from atmospheric turbulence as well as from effects intrinsic to certain detectors. Here, we describe the design and performance of the half wave plate rotator and achromatic half-wave plate for the the new imaging polarimeter, TolTEC. These components are mounted in front of the cryostat window and operate at ambient temperature. The Half-Wave Plate Rotator (HWPR) spins the half-wave plate at 2 revolutions per second. The rotation mechanism consists of nine air bearings to provide low-friction motion and a frameless torque motor to directly drive rotation. The orientation of the rotor and half-wave plate are recorded using a high-precision optical encoder. We review the experimental requirements and technical design of the rotator as well as the associated electronics, pneumatics, and software.

The Next Generation Balloon-borne Large Aperture Submillimeter Telescope (BLAST-TNG) is a submillimeter mapping experiment planned for a 28 day long-duration balloon (LDB) flight from McMurdo Station, Antarctica during the 2018-2019 season. BLAST-TNG will detect submillimeter polarized interstellar dust emission, tracing magnetic fields in galactic molecular clouds. BLAST-TNG will be the first polarimeter with the sensitivity and resolution to probe the ~0.1 parsec-scale features that are critical to understanding the origin of structures in the interstellar medium. BLAST-TNG features three detector arrays operating at wavelengths of 250, 350, and 500 m (1200, 857, and 600 GHz) comprised of 918, 469, and 272 dual-polarization pixels, respectively. Each pixel is made up of two crossed microwave kinetic inductance detectors (MKIDs). These arrays are cooled to 275 mK in a cryogenic receiver. Each MKID has a different resonant frequency, allowing hundreds of resonators to be read out on a single transmission line. This inherent ability to be frequency-domain multiplexed simplifies the cryogenic readout hardware, but requires careful optical testing to map out the physical location of each resonator on the focal plane. Receiver-level optical testing was carried out using both a cryogenic source mounted to a movable xy-stage with a shutter, and a beam-filling, heated blackbody source able to provide a 10-50 C temperature chop. The focal plane array noise properties, responsivity, polarization efficiency, instrumental polarization were measured. We present the preflight characterization of the BLAST-TNG cryogenic system and array-level optical testing of the MKID detector arrays in the flight receiver.

BFORE 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.

The Balloon-borne Large Aperture Submillimeter Telescope for Polarimetry (BLASTPol) is a suborbital mapping experiment designed to study the role magnetic fields play in star formation. BLASTPol has had two science flights from McMurdo Station, Antarctica in 2010 and 2012. These flights have produced thousands of polarization vectors at 250, 350 and 500 microns in several molecular cloud targets. We present the design, specifications, and progress towards the next-generation BLASTPol experiment (BLAST-TNG). BLAST-TNG will fly a 40% larger diameter primary mirror, with almost 8 times the number of polarization-sensitive detectors resulting in a factor of 16 increase in mapping speed. With a spatial resolution of 2200 and four times the field of view (340 arcmin2) of BLASTPol, BLAST-TNG will bridge the angular scales between Planck's all-sky maps with 50 resolution and ALMA's ultra-high resolution narrow (~ 2000) fields. The new receiver has a larger cryogenics volume, allowing for a 28 day hold time. BLAST-TNG employs three arrays of Microwave Kinetic Inductance Detectors (MKIDs) with 30% fractional bandwidth at 250, 350 and 500 microns. In this paper, we will present the new BLAST-TNG instrument and science objectives. © (2014) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

The Balloon-borne Large Aperture Submillimeter Telescope for Polarimetry (BLASTPol) is a suborbital mapping experiment designed to study the role played by magnetic fields in the star formation process. BLASTPol uses a total power instrument and an achromatic half-wave plate to modulate the polarization signal. During its first flight from Antarctica in December 2010, BLASTPol made degree scale maps of linearly polarized dust emission from molecular clouds in three wavebands centered at 250, 350, and 500 μm. This unprecedented dataset in terms of sky coverage, with sub-arcminute resolution, allows BLASTPol to trace magnetic fields in star-forming regions at scales ranging from cores to entire molecular cloud complexes. A second long-duration flight is scheduled for December 2012.© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.