140 research outputs found
Overview of the spectrometer optical fiber feed for the Habitable-zone Planet Finder
The Habitable-zone Planet Finder (HPF) is a highly stabilized fiber fed
precision radial velocity (RV) spectrograph working in the Near Infrared (NIR):
810 - 1280 nm . In this paper we present an overview of the preparation of the
optical fibers for HPF. The entire fiber train from the telescope focus down to
the cryostat is detailed. We also discuss the fiber polishing, splicing and its
integration into the instrument using a fused silica puck. HPF was designed to
be able to operate in two modes, High Resolution (HR- the only mode mode
currently commissioned) and High Efficiency (HE). We discuss these fiber heads
and the procedure we adopted to attach the slit on to the HR fibers.Comment: Presented at 2018 SPIE Astronomical Telescopes + Instrumentation,
Austin, Texas, USA. 18 pages, 25 figures, and 2 table
Electroencephalographic biofeedback in the treatment of attention-deficit/hyperactivity disorder.
Historically, pharmacological treatments for attention-deficit/hyperactivity disorde
Electroencephalographic biofeedback in the treatment of attention-deficit/hyperactivity disorder.
Historically, pharmacological treatments for attention-deficit/hyperactivity disorde
Harnessing content and context for enhanced decision making
In a time in which a significant amount of interpersonal interactions
take place online, one must enquire to which extent are these
milieus suitable for supporting the complexity of our communication.
This is especially important in more sensitive domains, such as the one of
Online Dispute Resolution, in which inefficient communication environments
may result in misunderstandings, poor decisions or the escalation
of the conflict. The conflict manager, in particular, may find his skills
severely diminished, namely in what concerns the accurate perception of
the state of the parties. In this paper the development of a rich communication
framework is detailed that conveys contextual information about
their users, harnessed from the transparent analysis of their behaviour
while communicating. Using it, the conflict manager may not only better
perceive the conflict and how it affects each party but also take better
contextualized decisions, closer to the ones taken in face-to-face settings.This work is part-funded by ERDF - European Regional Development Fund
through the COMPETE Programme (operational programme for competitiveness)
and by National Funds through the FCT { Fundação para a Ciência e a
Tecnologia (Portuguese Foundation for Science and Technology) within project
FCOMP-01-0124-FEDER-028980 (PTDC/EEI-SII/1386/2012) and project PEst-
OE/EEI/UI0752/2014
Ghosts of NEID's Past
The NEID spectrograph is a R 120,000 resolution fiber-fed and highly
stabilized spectrograph for extreme radial velocity (RV) precision. It is being
commissioned at the 3.5 m WIYN telescope in Kitt Peak National Observatory with
a desired instrumental precision of better than 30 \cms{}. NEID's bandpass of
380 -- 930 nm enables the simultaneous wavelength coverage of activity
indicators from the Ca HK lines in the blue to the Ca IR triplet in the IR. In
this paper we will present our efforts to characterize and mitigate optical
ghosts in the NEID spectrograph during assembly, integration and testing, and
highlight several of the dominant optical element contributors such as the
cross dispersion prism and input optics. We shall present simulations of the
2-D spectrum and discuss the predicted ghost features on the focal plane, and
how they may impact the RV performance for NEID. We also present the mitigation
strategy adopted for each ghost which may be applied to future instrument
designs. This work will enable other instrument builders to potentially avoid
some of these issues, as well as outline mitigation strategies.Comment: Conference Proceeding from SPIE Astronomical Telescopes +
Instrumentation (2020): 12 page
TOI-1670 c, a 40-day Orbital Period Warm Jupiter in a Compact System, is Well-aligned
We report the measurement of the sky-projected obliquity angle of
the Warm Jovian exoplanet TOI-1670 c via the Rossiter-McLaughlin effect as part
of the Stellar Obliquities in Long-period Exoplanet Systems (SOLES) project. We
observed the transit window during UT 20 April 2023 for 7 continuous hours with
NEID on the 3.5 m WIYN Telescope at Kitt Peak National Observatory. TOI-1670
hosts a sub-Neptune (P ~11 days; planet b) interior to the Warm Jovian (P ~40
days; planet c), which presents an opportunity to investigate the dynamics of a
Warm Jupiter with an inner companion. Additionally, TOI-1670 c is now among the
longest-period planets to date to have its sky-projected obliquity angle
measured. We find planet c is well-aligned to the host star, with =
-0.3 +/- 2.2 degrees. TOI-1670 c joins a growing census of aligned Warm
Jupiters around single stars and aligned planets in multi-planet systems.Comment: 11 pages, 2 figures, 1 table. Accepted to ApJ Letter
Stable fiber-illumination for extremely precise radial velocities with NEID
NEID is a high-resolution red-optical precision radial velocity (RV)
spectrograph recently commissioned at the WIYN 3.5 m telescope at Kitt Peak
National Observatory, Arizona, USA. NEID has an extremely stable environmental
control system, and spans a wavelength range of 380 to 930 nm with two
observing modes: a High Resolution (HR) mode at R 112,000 for maximum RV
precision, and a High Efficiency (HE) mode at R 72,000 for faint
targets. In this manuscript we present a detailed description of the components
of NEID's optical fiber feed, which include the instrument, exposure meter,
calibration system, and telescope fibers. Many parts of the optical fiber feed
can lead to uncalibratable RV errors, which cannot be corrected for using a
stable wavelength reference source. We show how these errors directly cascade
down to performance requirements on the fiber feed and the scrambling system.
We detail the design, assembly, and testing of each component. Designed and
built from the bottom-up with a single-visit instrument precision requirement
of 27 , close attention was paid to the error contribution
from each NEID subsystem. Finally, we include the lab and on-sky tests
performed during instrument commissioning to test the illumination stability,
and discuss the path to achieving the instrumental stability required to search
for a true Earth twin around a Solar-type star.Comment: Accepted in A
Overview of the spectrometer optical fiber feed for the habitable-zone planet finder
The Habitable-zone Planet Finder (HPF) is a highly stabilized fiber fed precision radial velocity (RV) spec- trograph working in the Near Infrared (NIR): 810 – 1280 nm. In this paper we present an overview of the preparation of the optical fibers for HPF. The entire fiber train from the telescope focus down to the cryostat is detailed. We also discuss the fiber polishing, splicing and its integration into the instrument using a fused silica puck. HPF was designed to be able to operate in two modes, High Resolution (HR- the only mode mode currently commissioned) and High Efficiency (HE). We discuss these fiber heads and the procedure we adopted to attach the slit on to the HR fibers
Stellar Spectroscopy in the Near-infrared with a Laser Frequency Comb
The discovery and characterization of exoplanets around nearby stars is
driven by profound scientific questions about the uniqueness of Earth and our
Solar System, and the conditions under which life could exist elsewhere in our
Galaxy. Doppler spectroscopy, or the radial velocity (RV) technique, has been
used extensively to identify hundreds of exoplanets, but with notable
challenges in detecting terrestrial mass planets orbiting within habitable
zones. We describe infrared RV spectroscopy at the 10 m Hobby-Eberly telescope
that leverages a 30 GHz electro-optic laser frequency comb with nanophotonic
supercontinuum to calibrate the Habitable Zone Planet Finder spectrograph.
Demonstrated instrument precision <10 cm/s and stellar RVs approaching 1 m/s
open the path to discovery and confirmation of habitable zone planets around
M-dwarfs, the most ubiquitous type of stars in our Galaxy
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