691 research outputs found
Explosive Transient Camera (ETC) Program
Since the inception of the ETC program, a wide range of new technologies was developed to support this astronomical instrument. The prototype unit was installed at ETC Site 1. The first partially automated observations were made and some major renovations were later added to the ETC hardware. The ETC was outfitted with new thermoelectrically-cooled CCD cameras and a sophisticated vacuum manifold, which, together, made the ETC a much more reliable unit than the prototype. The ETC instrumentation and building were placed under full computer control, allowing the ETC to operate as an automated, autonomous instrument with virtually no human intervention necessary. The first fully-automated operation of the ETC was performed, during which the ETC monitored the error region of the repeating soft gamma-ray burster SGR 1806-21
Transiting Exoplanet Survey Satellite (TESS)
The Transiting Exoplanet Survey Satellite (TESS ) will search for planets transiting bright and nearby stars. TESS has been selected by NASA for launch in 2017 as an Astrophysics Explorer mission. The spacecraft will be placed into a highly elliptical 13.7-day orbit around the Earth. During its two-year mission, TESS will employ four wide-field optical CCD cameras to monitor at least 200,000 main-sequence dwarf stars with I_C (approximately less than) 13 for temporary drops in brightness caused by planetary transits. Each star will be observed for an interval ranging from one month to one year, depending mainly on the star's ecliptic latitude. The longest observing intervals will be for stars near the ecliptic poles, which are the optimal locations for follow-up observations with the James Webb Space Telescope. Brightness measurements of preselected target stars will be recorded every 2 min, and full frame images will be recorded every 30 min. TESS stars will be 10-100 times brighter than those surveyed by the pioneering Kepler mission. This will make TESS planets easier to characterize with follow-up observations. TESS is expected to find more than a thousand planets smaller than Neptune, including dozens that are comparable in size to the Earth. Public data releases will occur every four months, inviting immediate community-wide efforts to study the new planets. The TESS legacy will be a catalog of the nearest and brightest stars hosting transiting planets, which will endure as highly favorable targets for detailed investigations
An improved redshift indicator for Gamma-Ray Bursts, based on the prompt emission
We propose an improved version of the redshift indicator developed by Atteia
(2003), which gets rid of the dependence on the burst duration and provides
better estimates for high-redshift GRBs. We present the derivation and the
definition of this redshift indicator, then its calibration with 17 GRBs with
known redshifts detected by HETE-2 and 2 more detected by Konus-Wind. We also
provide an estimation of the redshift for 59 bursts, and we finally discuss the
redshift distribution of HETE-bursts and the possible other applications of
this redshift indicator.Comment: To appear in the proceedings of the 16th Annual October Astrophysics
Conference in Maryland, "Gamma Ray Bursts in the Swift Era", Washington DC.,
November 29-December 2, 2005, 4 pages, 3 figure
The Space System for the High Energy Transient Experiment
The High Energy Transient Experiment (HETE) is an astrophysics project funded by NASA and led by the Center for Space Research (CSR) at the Massachusetts Institute of Technology (MIT). It has for principal goal the detection and precise localization of the still mysterious sources of gamma ray bursts. The project is original in many respects. HETE will provide simultaneous observations of bursts in the gamma, X-ray and UV ranges from the same small (250 Ibms) space platform. A network of ground stations around the world will diffuse in real time key information derived from HETE observations to many ground observatories, allowing quick follow-on observations with ground instruments. The whole project is entirely managed by MIT, under top level NASA supervision, and satellite and ground stations will be remotely operated from CSA. The HETE system development is conducted with a small budget and under a short schedule
Event-driven charge-coupled device design and applications therefor
An event-driven X-ray CCD imager device uses a floating-gate amplifier or other non-destructive readout device to non-destructively sense a charge level in a charge packet associated with a pixel. The output of the floating-gate amplifier is used to identify each pixel that has a charge level above a predetermined threshold. If the charge level is above a predetermined threshold the charge in the triggering charge packet and in the charge packets from neighboring pixels need to be measured accurately. A charge delay register is included in the event-driven X-ray CCD imager device to enable recovery of the charge packets from neighboring pixels for accurate measurement. When a charge packet reaches the end of the charge delay register, control logic either dumps the charge packet, or steers the charge packet to a charge FIFO to preserve it if the charge packet is determined to be a packet that needs accurate measurement. A floating-diffusion amplifier or other low-noise output stage device, which converts charge level to a voltage level with high precision, provides final measurement of the charge packets. The voltage level is eventually digitized by a high linearity ADC
Searching for Gravitational-Wave Counterparts using the Transiting Exoplanet Survey Satellite
In 2017, the LIGO and Virgo gravitational wave (GW) detectors, in conjunction
with electromagnetic (EM) astronomers, observed the first GW multi-messenger
astrophysical event, the binary neutron star (BNS) merger GW170817. This marked
the beginning of a new era in multi-messenger astrophysics. To discover further
GW multi-messenger events, we explore the synergies between the Transiting
Exoplanet Survey Satellite (TESS) and GW observations triggered by the
LIGO-Virgo-KAGRA Collaboration (LVK) detector network. TESS's extremely wide
field of view of ~2300 deg^2 means that it could overlap with large swaths of
GW localizations, which can often span hundreds of deg^2 or more. In this work,
we use a recently developed transient detection pipeline to search TESS data
collected during the LVK's third observing run, O3, for any EM counterparts. We
find no obvious counterparts brighter than about 17th magnitude in the TESS
bandpass. Additionally, we present end-to-end simulations of BNS mergers,
including their detection in GWs and simulations of light curves, to identify
TESS's kilonova discovery potential for the LVK's next observing run (O4). In
the most optimistic case, TESS will observe up to one GW-found BNS merger
counterpart per year. However, TESS may also find up to five kilonovae which
did not trigger the LVK network, emphasizing that EM-triggered GW searches may
play a key role in future kilonova detections. We also discuss how TESS can
help place limits on EM emission from binary black hole mergers, and rapidly
exclude large sky areas for poorly localized GW events.Comment: 16 pages, 7 figures, 2 tables. Submitted to AAS Journal
Multi-messenger astrophysics in the gravitational-wave era
The observation of GW170817, the first binary neutron star merger observed in
both gravitational waves (GW) and electromagnetic (EM) waves, kickstarted the
age of multi-messenger GW astronomy. This new technique presents an
observationally rich way to probe extreme astrophysical processes. With the
onset of the LIGO-Virgo-KAGRA Collaboration's O4 observing run and wide-field
EM instruments well-suited for transient searches, multi-messenger astrophysics
has never been so promising. We review recent searches and results for
multi-messenger counterparts to GW events, and describe existing and upcoming
EM follow-up facilities, with a particular focus on WINTER, a new near-infrared
survey telescope, and TESS, an exoplanet survey space telescope.Comment: 5 pages, 1 figure, proceedings from TAUP 202
Quick-Look Pipeline Light Curves for 5.7 Million Stars Observed Over the Second Year of TESS' First Extended Mission
We present High-Level Science Products (HLSPs) containing light curves from
MIT's Quick-Look Pipeline (QLP) from the second year of TESS' first Extended
Mission (Sectors 40 - 55; 2021 July - 2022 September). In total, 12.2 million
per-sector light curves for 5.7 million unique stars were extracted from
10-minute cadence Full-Frame Images (FFIs) and are made available to the
community. As in previous deliveries, QLP HLSPs include both raw and detrended
flux time series for all observed stars brighter than TESS magnitude T = 13.5
mag. Starting in Sector 41, QLP also produces light curves for select fainter M
dwarfs. QLP has provided the community with one of the largest sources of
FFI-extracted light curves to date since the start of the TESS mission.Comment: 3 pages, 1 figur
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