Abstract There have been a variety of proposals for a long-wavelength radio astronomical telescop... more Abstract There have been a variety of proposals for a long-wavelength radio astronomical telescope on the Moon since soon after the first human landings. We highlight two aspects of the Moon that make it particularly appealing for long-wavelength radio astronomy. 1. ...
"What were the first objects to light up the universe, and when did they do it"? (NRC, ... more "What were the first objects to light up the universe, and when did they do it"? (NRC, 2011). These are among the most fundamental questions in modern astrophysics and cosmology as articulated in the recent NRC report, New Worlds, New Horizons in Astronomy and Astrophysics. The Astro2010 Decadal Survey singles out this epoch as one of the top three science objectives for the coming decade. The birth of the first stars and black holes - the end of the Dark Ages or the "Cosmic Dawn'' - is one of the truly transformative events in the history of the Universe. It provides the key connection between observations of the extraordinarily smooth Universe 400,000 years after the Big Bang seen via the Cosmic Microwave Background, and telescopic images that reveal the wealth of structures and galaxies seen today. Unfortunately, this epoch has remained tantalizingly out of reach for decades and its exploration requires fundamentally new techniques. With the Dark Ages Radio Explorer (DARE), we will investigate this early epoch of the Universe ( 80-350 million years after the Big Bang) for the first time using the sky-averaged, redshifted 21-cm Background (z=13-35) arising from the time when the first stars and black holes appeared in the Universe. DARE consists of a pair of tapered dipole antennas in lunar orbit operating in the shielded zone above the farside at 40-120 MHz. In this talk, we will discuss the science objectives and the instrument package for DARE.
We report the discovery of two pulsars 11' from Sgr A* in the same pointing from our 2007 Gal... more We report the discovery of two pulsars 11' from Sgr A* in the same pointing from our 2007 Galactic Center survey with the Green Bank telescope at 2 GHz. J1746-2850I has a period of 1.077 s and dispersion measure of 944 pc/cc and a preliminary timing solution indicates that this may be a young pulsar born with a strong magnetic
Observations at radio wavelengths address key problems in astrophysics, astrobiology, and lunar s... more Observations at radio wavelengths address key problems in astrophysics, astrobiology, and lunar structure including the first light in the Universe (the Epoch of Reionization), the presence of magnetic fields around extrasolar planets, particle acceleration mechanisms, and the structure of the lunar ionosphere. Moreover, achieving the performance needed to address these scientific questions demands observations at wavelengths longer than those that
All of the solar system giant planets and the Earth produce radio wavelength emissions as a resul... more All of the solar system giant planets and the Earth produce radio wavelength emissions as a result of an interaction between their magnetic fields and the solar wind. Indirect evidence for at least some extrasolar giant planets also having magnetic fields includes the modulation of calcium emission lines of their host stars phased with the planetary orbits likely due to magnetic reconnection events between the stellar and planetary fields. If magnetic fields are a generic property of giant planets, then extrasolar giant planets should emit at radio wavelengths allowing for their direct detection. From magnetospheric emissions it may be possible to infer various planetary properties, including constraints on planetary interiors, planetary rotation rates, the existence of satellites, and the retention of atmospheres. In the case of the Earth, its magnetic field may contribute to its habitability by protecting its atmosphere from solar wind erosion and by preventing energetic particles...
A variety of sources are predicted to emit at meter wavelengths and would likely appear as transi... more A variety of sources are predicted to emit at meter wavelengths and would likely appear as transients. This source list includes extrasolar planets, brown dwarfs, and prompt emission from gamma ray bursts. Low frequency VLA observations are well suited to probe the dynamic radio sky, given the the large field of view (> 150 deg2) at 74 MHz and sub-mJy sensitivity at 325 MHz. We present results from various low frequency radio transient searches using data from the VLA archive, a rich reservoir of largely unsearched data. In particular, we report on multiple 325 MHz searches using targeted fields and an all-sky search using fields from the 74 MHz VLA Low frequency Sky Survey (VLSS). The VLSS variability and transient emission search is the largest to date, covering over 3 pi steradians with minute to multi-year flux measurements of 50,000 field sources.
2013 US National Committee of URSI National Radio Science Meeting (USNC-URSI NRSM), 2013
ABSTRACT The Dark Ages Radio Explorer (DARE) is a concept for a space-based cosmology mission des... more ABSTRACT The Dark Ages Radio Explorer (DARE) is a concept for a space-based cosmology mission designed to measure the sky-averaged spectrum from the highly-redshifted hyperfine 21 cm transition from neutral hydrogen (J.O. Burns, J. Lazio, et al., Adv. Space Res., 49, 433-450, 2012). From this sky-averaged spectrum, the formation of the first luminous objects at the end of the Dark Ages and during Cosmic Dawn (redshifts z = 11-35) can be tracked by their effect on the neutral intergalactic medium. The specific science objectives for the DARE mission are (1) When did the first stars form? (2) When did the first accreting black holes form? (3) When did Reionization begin? (4) What surprises does the end of the Dark Ages hold (e.g., dark matter decay)? The DARE spacecraft orbits the Moon for a mission lifetime of 3 years and takes data above the lunar farside, the only location in the inner solar system proven to be free of human-generated radio frequency interference and any significant ionosphere.
Observations of the HI 21 cm transition line promises to be an important probe into the cosmic Da... more Observations of the HI 21 cm transition line promises to be an important probe into the cosmic Dark Ages and Epoch of Reionization. The Dark Ages Radio Explorer (DARE) is designed to measure the sky-averaged 21-cm signal from this cosmic age using a single radiometer operating between 40-120 MHz (redshifts z=11-35). DARE will orbit the Moon for a mission lifetime of ≤ 3 years and take data above the lunar far side, where it is shielded from the Earth's intense interference. The science objectives of DARE include formation of first stars, first accreting black holes, beginning of reionization and end of the Dark Ages. The science instrument is composed of a three-element radiometer, including electrically-short, tapered, bi-conical dipole antennas, a receiver, and a digital spectrometer. Although the TRL (Technology Readiness Level) of the individual components of DARE instrument is high, the overall instrument TRL is low. One of the main aim of the entire DARE team is to advance...
The Dark Ages Radio Explorer (DARE) is a mission concept designed to measure the sky-averaged red... more The Dark Ages Radio Explorer (DARE) is a mission concept designed to measure the sky-averaged redshifted HI 21-cm signal from the cosmic Dark Ages and Epoch of Reionization between 40 - 120 MHz (z = 11 - 35). DARE will orbit the Moon for a mission lifetime of 3 years and take data above the lunar far side, where it is shielded from the intense human-generated radio-frequency interference (RFI) found on Earth. The science objectives of DARE include charting the history of the formation of the first stars, first accreting black holes, beginning of reionization, and end of the Dark Ages. A prototype science instrument has been constructed, consisting of bi-conical dipole antennas and a differential amplifier balun followed by a receiver and JPL-Caltech designed digital spectrometer. Extensive tests with this instrument are underway in order to improve the Technology Readiness Level (TRL) of the overall DARE instrument. Here, we present results from preliminary field tests at the Nation...
Abstract There have been a variety of proposals for a long-wavelength radio astronomical telescop... more Abstract There have been a variety of proposals for a long-wavelength radio astronomical telescope on the Moon since soon after the first human landings. We highlight two aspects of the Moon that make it particularly appealing for long-wavelength radio astronomy. 1. ...
"What were the first objects to light up the universe, and when did they do it"? (NRC, ... more "What were the first objects to light up the universe, and when did they do it"? (NRC, 2011). These are among the most fundamental questions in modern astrophysics and cosmology as articulated in the recent NRC report, New Worlds, New Horizons in Astronomy and Astrophysics. The Astro2010 Decadal Survey singles out this epoch as one of the top three science objectives for the coming decade. The birth of the first stars and black holes - the end of the Dark Ages or the "Cosmic Dawn'' - is one of the truly transformative events in the history of the Universe. It provides the key connection between observations of the extraordinarily smooth Universe 400,000 years after the Big Bang seen via the Cosmic Microwave Background, and telescopic images that reveal the wealth of structures and galaxies seen today. Unfortunately, this epoch has remained tantalizingly out of reach for decades and its exploration requires fundamentally new techniques. With the Dark Ages Radio Explorer (DARE), we will investigate this early epoch of the Universe ( 80-350 million years after the Big Bang) for the first time using the sky-averaged, redshifted 21-cm Background (z=13-35) arising from the time when the first stars and black holes appeared in the Universe. DARE consists of a pair of tapered dipole antennas in lunar orbit operating in the shielded zone above the farside at 40-120 MHz. In this talk, we will discuss the science objectives and the instrument package for DARE.
We report the discovery of two pulsars 11' from Sgr A* in the same pointing from our 2007 Gal... more We report the discovery of two pulsars 11' from Sgr A* in the same pointing from our 2007 Galactic Center survey with the Green Bank telescope at 2 GHz. J1746-2850I has a period of 1.077 s and dispersion measure of 944 pc/cc and a preliminary timing solution indicates that this may be a young pulsar born with a strong magnetic
Observations at radio wavelengths address key problems in astrophysics, astrobiology, and lunar s... more Observations at radio wavelengths address key problems in astrophysics, astrobiology, and lunar structure including the first light in the Universe (the Epoch of Reionization), the presence of magnetic fields around extrasolar planets, particle acceleration mechanisms, and the structure of the lunar ionosphere. Moreover, achieving the performance needed to address these scientific questions demands observations at wavelengths longer than those that
All of the solar system giant planets and the Earth produce radio wavelength emissions as a resul... more All of the solar system giant planets and the Earth produce radio wavelength emissions as a result of an interaction between their magnetic fields and the solar wind. Indirect evidence for at least some extrasolar giant planets also having magnetic fields includes the modulation of calcium emission lines of their host stars phased with the planetary orbits likely due to magnetic reconnection events between the stellar and planetary fields. If magnetic fields are a generic property of giant planets, then extrasolar giant planets should emit at radio wavelengths allowing for their direct detection. From magnetospheric emissions it may be possible to infer various planetary properties, including constraints on planetary interiors, planetary rotation rates, the existence of satellites, and the retention of atmospheres. In the case of the Earth, its magnetic field may contribute to its habitability by protecting its atmosphere from solar wind erosion and by preventing energetic particles...
A variety of sources are predicted to emit at meter wavelengths and would likely appear as transi... more A variety of sources are predicted to emit at meter wavelengths and would likely appear as transients. This source list includes extrasolar planets, brown dwarfs, and prompt emission from gamma ray bursts. Low frequency VLA observations are well suited to probe the dynamic radio sky, given the the large field of view (> 150 deg2) at 74 MHz and sub-mJy sensitivity at 325 MHz. We present results from various low frequency radio transient searches using data from the VLA archive, a rich reservoir of largely unsearched data. In particular, we report on multiple 325 MHz searches using targeted fields and an all-sky search using fields from the 74 MHz VLA Low frequency Sky Survey (VLSS). The VLSS variability and transient emission search is the largest to date, covering over 3 pi steradians with minute to multi-year flux measurements of 50,000 field sources.
2013 US National Committee of URSI National Radio Science Meeting (USNC-URSI NRSM), 2013
ABSTRACT The Dark Ages Radio Explorer (DARE) is a concept for a space-based cosmology mission des... more ABSTRACT The Dark Ages Radio Explorer (DARE) is a concept for a space-based cosmology mission designed to measure the sky-averaged spectrum from the highly-redshifted hyperfine 21 cm transition from neutral hydrogen (J.O. Burns, J. Lazio, et al., Adv. Space Res., 49, 433-450, 2012). From this sky-averaged spectrum, the formation of the first luminous objects at the end of the Dark Ages and during Cosmic Dawn (redshifts z = 11-35) can be tracked by their effect on the neutral intergalactic medium. The specific science objectives for the DARE mission are (1) When did the first stars form? (2) When did the first accreting black holes form? (3) When did Reionization begin? (4) What surprises does the end of the Dark Ages hold (e.g., dark matter decay)? The DARE spacecraft orbits the Moon for a mission lifetime of 3 years and takes data above the lunar farside, the only location in the inner solar system proven to be free of human-generated radio frequency interference and any significant ionosphere.
Observations of the HI 21 cm transition line promises to be an important probe into the cosmic Da... more Observations of the HI 21 cm transition line promises to be an important probe into the cosmic Dark Ages and Epoch of Reionization. The Dark Ages Radio Explorer (DARE) is designed to measure the sky-averaged 21-cm signal from this cosmic age using a single radiometer operating between 40-120 MHz (redshifts z=11-35). DARE will orbit the Moon for a mission lifetime of ≤ 3 years and take data above the lunar far side, where it is shielded from the Earth's intense interference. The science objectives of DARE include formation of first stars, first accreting black holes, beginning of reionization and end of the Dark Ages. The science instrument is composed of a three-element radiometer, including electrically-short, tapered, bi-conical dipole antennas, a receiver, and a digital spectrometer. Although the TRL (Technology Readiness Level) of the individual components of DARE instrument is high, the overall instrument TRL is low. One of the main aim of the entire DARE team is to advance...
The Dark Ages Radio Explorer (DARE) is a mission concept designed to measure the sky-averaged red... more The Dark Ages Radio Explorer (DARE) is a mission concept designed to measure the sky-averaged redshifted HI 21-cm signal from the cosmic Dark Ages and Epoch of Reionization between 40 - 120 MHz (z = 11 - 35). DARE will orbit the Moon for a mission lifetime of 3 years and take data above the lunar far side, where it is shielded from the intense human-generated radio-frequency interference (RFI) found on Earth. The science objectives of DARE include charting the history of the formation of the first stars, first accreting black holes, beginning of reionization, and end of the Dark Ages. A prototype science instrument has been constructed, consisting of bi-conical dipole antennas and a differential amplifier balun followed by a receiver and JPL-Caltech designed digital spectrometer. Extensive tests with this instrument are underway in order to improve the Technology Readiness Level (TRL) of the overall DARE instrument. Here, we present results from preliminary field tests at the Nation...
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