23 research outputs found
Association of Early Life Stressors with Deficits in Child and Adolescent Cognitive Functioning
The purpose of this study was to determine whether the ACEs questionnaire could be a viable screener tool for identifying children in need of neuropsychological testing. This study consisted of a sample of child participants aged 8-17 years (N=53) who were divided into a no ACEs group or the ACEs group (1 or more ACEs) depending on parental responses to the ACEs questionnaire. Participants completed a series of virtual neuropsychological tests that assessed overall neurocognitive functioning, memory, and attention. No significant differences between the no ACEs group and the ACEs group in performance of the overall Neurocognitive Index, Composite Memory Index, or Complex Attention Index emerged. While no significant differences were found in this study, the demographic make-up of the sample could in part explain the absence of significant findings. The sample for this study included highly educated parents who resided in a higher SES bracket. These and other limitations are discussed. While this study did have limitations, several future directions were identified that would strengthen this area of research
Toward Eclipse Mapping of Hot Jupiters
Recent Spitzer infrared measurements of hot Jupiter eclipses suggest that
eclipse mapping techniques could be used to spatially resolve the day-side
photospheric emission of these planets using partial occultations. As a first
step in this direction, we simulate ingress/egress lightcurves for the three
brightest known eclipsing hot Jupiters and evaluate the degree to which
parameterized photospheric emission models can be distinguished from each other
with repeated, noisy eclipse measurements. We find that the photometric
accuracy of Spitzer is insufficient to use this tool effectively. On the other
hand, the level of photospheric details that could be probed with a few JWST
eclipse measurements could greatly inform hot Jupiter atmospheric modeling
efforts. A JWST program focused on non-parametric eclipse map inversions for
hot Jupiters should be actively considered.Comment: 32 pages, 6 figures, 3 tables, accepted for publication in Ap
Possible thermochemical disequilibrium in the atmosphere of the exoplanet GJ 436b
The nearby extrasolar planet GJ 436b--which has been labelled as a 'hot
Neptune'--reveals itself by the dimming of light as it crosses in front of and
behind its parent star as seen from Earth. Respectively known as the primary
transit and secondary eclipse, the former constrains the planet's radius and
mass, and the latter constrains the planet's temperature and, with measurements
at multiple wavelengths, its atmospheric composition. Previous work using
transmission spectroscopy failed to detect the 1.4-\mu m water vapour band,
leaving the planet's atmospheric composition poorly constrained. Here we report
the detection of planetary thermal emission from the dayside of GJ 436b at
multiple infrared wavelengths during the secondary eclipse. The best-fit
compositional models contain a high CO abundance and a substantial methane
(CH4) deficiency relative to thermochemical equilibrium models for the
predicted hydrogen-dominated atmosphere. Moreover, we report the presence of
some H2O and traces of CO2. Because CH4 is expected to be the dominant
carbon-bearing species, disequilibrium processes such as vertical mixing and
polymerization of methane into substances such as ethylene may be required to
explain the hot Neptune's small CH4-to-CO ratio, which is at least 10^5 times
smaller than predicted
Spitzer phase curve observations and circulation models of the inflated ultra-hot Jupiter WASP-76b
The large radii of many hot Jupiters can only be matched by models that have
hot interior adiabats, and recent theoretical work has shown that the interior
evolution of hot Jupiters has a significant impact on their atmospheric
structure. Due to its inflated radius, low gravity, and ultra-hot equilibrium
temperature, WASP-76b is an ideal case study for the impact of internal
evolution on observable properties. Hot interiors should most strongly affect
the non-irradiated side of the planet, and thus full phase curve observations
are critical to ascertain the effect of the interior on the atmospheres of hot
Jupiters. In this work, we present the first Spitzer phase curve observations
of WASP-76b. We find that WASP-76b has an ultra-hot day side and relatively
cold nightside with brightness temperatures of / at 3.6~\micron and / at 4.5~\micron, respectively. These results provide evidence
for a dayside thermal inversion. Both channels exhibit small phase offsets of
at 3.6~\micron and at
. We compare our observations to a suite of general
circulation models that consider two end-members of interior temperature along
with a broad range of frictional drag strengths. Strong frictional drag is
necessary to match the small phase offsets and cold nightside temperatures
observed. From our suite of cloud-free GCMs, we find that only cases with a
cold interior can reproduce the cold nightsides and large phase curve amplitude
at 4.5~\micron, hinting that the hot interior adiabat of WASP-76b does not
significantly impact its atmospheric dynamics or that clouds blanket its
nightside.Comment: 24 pages, 10 Figures, 5 Tables. Accepted to AJ. Co-First Author
Smaller than expected bright-spot offsets in Spitzer phase curves of the hot Jupiter Qatar-1b
We present \textit{Spitzer} full-orbit thermal phase curves of the hot
Jupiter Qatar-1b, a planet with the same equilibrium temperature---and
intermediate surface gravity and orbital period---as the well-studied planets
HD 209458b and WASP-43b. We measure secondary eclipse of at
m and at m, corresponding to dayside
brightness temperatures of ~K and ~K,
respectively, consistent with a vertically isothermal dayside. The respective
nightside brightness temperatures are ~K and
~K, in line with a trend that hot Jupiters all have similar
nightside temperatures. We infer a Bond albedo of and a
moderate day-night heat recirculation efficiency, similar to HD 209458b.
General circulation models for HD 209458b and WASP-43b predict that their
bright-spots should be shifted east of the substellar point by tens of degrees,
and these predictions were previously confirmed with \textit{Spitzer}
full-orbit phase curve observations. The phase curves of Qatar-1b are likewise
expected to exhibit eastward offsets. Instead, the observed phase curves are
consistent with no offset: at m and
at m. The discrepancy in circulation
patterns between these three otherwise similar planets points to the importance
of secondary parameters like rotation rate and surface gravity, and the
presence or absence of clouds, in determining atmospheric conditions on hot
Jupiters.Comment: 14 pages, 8 figures. Accepted for publication in A
A Framework for Prioritizing the TESS Planetary Candidates Most Amenable to Atmospheric Characterization
A key legacy of the recently launched TESS mission will be to provide the
astronomical community with many of the best transiting exoplanet targets for
atmospheric characterization. However, time is of the essence to take full
advantage of this opportunity. JWST, although delayed, will still complete its
nominal five year mission on a timeline that motivates rapid identification,
confirmation, and mass measurement of the top atmospheric characterization
targets from TESS. Beyond JWST, future dedicated missions for atmospheric
studies such as ARIEL require the discovery and confirmation of several hundred
additional sub-Jovian size planets (R_p < 10 R_Earth) orbiting bright stars,
beyond those known today, to ensure a successful statistical census of
exoplanet atmospheres. Ground-based ELTs will also contribute to surveying the
atmospheres of the transiting planets discovered by TESS. Here we present a set
of two straightforward analytic metrics, quantifying the expected
signal-to-noise in transmission and thermal emission spectroscopy for a given
planet, that will allow the top atmospheric characterization targets to be
readily identified among the TESS planet candidates. Targets that meet our
proposed threshold values for these metrics would be encouraged for rapid
follow-up and confirmation via radial velocity mass measurements. Based on the
catalog of simulated TESS detections by Sullivan et al. (2015), we determine
appropriate cutoff values of the metrics, such that the TESS mission will
ultimately yield a sample of high-quality atmospheric
characterization targets across a range of planet size bins, extending down to
Earth-size, potentially habitable worlds.Comment: accepted to PAS
Recommended from our members
The effect of stellar contamination on low-resolution transmission spectroscopy: needs identified by NASAâs Exoplanet Exploration Program Study Analysis Group 21
Study Analysis Group 21 (SAG21) of NASAâs Exoplanet Exploration Program Analysis Group was organized to study the effect of stellar contamination on space-based transmission spectroscopy, a method for studying exoplanetary atmospheres by measuring the wavelength-dependent radius of a planet as it transits its star. Transmission spectroscopy relies on a precise understanding of the spectrum of the star being occulted. However, stars are not homogeneous, constant light sources but have temporally evolving photospheres and chromospheres with inhomogeneities like spots, faculae, plages, granules, and flares. This SAG brought together an interdisciplinary team of more than 100 scientists, with observers and theorists from the heliophysics, stellar astrophysics, planetary science, and exoplanetary atmosphere research communities, to study the current research needs that can be addressed in this context to make the most of transit studies from current NASA facilities like Hubble Space Telescope and JWST. The analysis produced 14 findings, which fall into three science themes encompassing (i) how the Sun is used as our best laboratory to calibrate our understanding of stellar heterogeneities (âThe Sun as the Stellar Benchmarkâ), (ii) how stars other than the Sun extend our knowledge of heterogeneities (âSurface Heterogeneities of Other Starsâ), and (iii) how to incorporate information gathered for the Sun and other stars into transit studies (âMapping Stellar Knowledge to Transit Studiesâ). In this invited review, we largely reproduce the final report of SAG21 as a contribution to the peer-reviewed literature