Abstract
We present a transit-timing variation (TTV) and planetary atmosphere analysis of the Neptune-mass planet HAT-P-26 b. We present a new set of 13 transit light curves from optical ground-based ...observations and combine them with light curves from the Wide Field Camera 3 on the Hubble Space Telescope, the Transiting Exoplanet Survey Satellite, and previously published ground-based data. We refine the planetary parameters of HAT-P-26 b and undertake a TTV analysis using 33 transits obtained over seven years. The TTV analysis shows an amplitude signal of 1.98 ± 0.05 minutes, which could result from the presence of an additional ∼0.02
M
Jup
planet at a 1:2 mean-motion resonance orbit. Using a combination of transit depths spanning optical to near-infrared wavelengths, we find that the atmosphere of HAT-P-26 b contains
2.4
−
1.6
+
2.9
% H
2
O with a derived temperature of
590
−
50
+
60
K.
Abstract
We predict that cyanoacetylene (HC
3
N) is produced photochemically in the atmosphere of GJ 1132 b in abundances detectable by the James Webb Space Telescope (JWST), assuming that the ...atmosphere is hydrogen dominated and rich in molecular nitrogen (N
2
), methane (CH
4
), and hydrogen cyanide (HCN), as described by Swain et al. First, we construct line lists and cross sections for HC
3
N. Then we apply these cross sections and the model atmosphere of Swain et al. to a radiative transfer model in order to simulate the transmission spectrum of GJ 1132 b as it would be seen by JWST, accounting for the uncertainty in the retrieved abundances. We predict that cyanoacetylene features at various wavelengths, with a clear lone feature at 4.5
μ
m, observable by JWST after one transit. This feature persists within the 1
σ
uncertainty of the retrieved abundances of HCN and CH
4
. The signal is detectable for stratospheric temperatures ≲600 K and moderate stratospheric mixing (10
6
cm
2
s
−1
≲
K
zz
≲ 10
8
cm
2
s
−1
). Our results also indicate that HC
3
N is an important source of opacity that future retrieval models should consider.
We predict that cyanoacetylene (HC$_3$N) is produced photochemically in the
atmosphere of GJ 1132 b in abundances detectable by the James Webb Space
Telescope (JWST), assuming that the atmosphere is ...hydrogen dominated and rich
in molecular nitrogen (N$_2$), methane (CH$_4$) and hydrogen cyanide (HCN), as
described by Swain et al. (2021). First, we construct line list and
cross-sections for HC$_3$N. Then we apply these cross-sections and the model
atmosphere of Swain et al. (2021) to a radiative transfer model in order to
simulate the transmission spectrum of GJ 1132 b as it would be seen by JWST,
accounting for the uncertainty in the retrieved abundances. We predict that
cyanoacetylene features at various wavelengths, with a clear lone feature at
4.5 $\mu$m, observable by JWST after one transit. This feature persists within
the $1-\sigma$ uncertainty of the retrieved abundances of HCN and CH$_4$. The
signal is detectable for stratospheric temperatures $\lesssim 600$ K and
moderate stratospheric mixing ($10^6 \, {\rm cm^2 \, s^{-1}} \lesssim K_{zz}
\lesssim 10^8 \, {\rm cm^2 \, s^{-1}}$). Our results also indicate that HC$_3$N
is an important source of opacity that future retrieval models should consider.
We present the transit timing variation (TTV) and planetary atmosphere analysis of the Neptune-mass planet HAT-P-26~b. We present a new set of 13 transit light curves from optical ground-based ...observations and combine them with light curves from the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST), Transiting Exoplanet Survey Satellite (TESS), and previously published ground-based data. We refine the planetary parameters of HAT-P-26 b and undertake a TTV analysis using 33 transits obtained over seven years. The TTV analysis shows an amplitude signal of 1.98 \(\pm\) 0.05 minutes, which could result from the presence of an additional \(0.02 M_{Jup}\) planet at the 1:2 mean-motion resonance orbit. Using a combination of transit depths spanning optical to near-infrared wavelengths, we find that the atmosphere of HAT-P-26 b contains \(2.4^{+2.9}_{-1.6}\)% of H\(_2\)O with a derived temperature of \(590^{+60}_{-50}\) K.
A Beginners Guide to Procedural Terrain Modelling Techniques Emmanuel, Kati Steven; Mathuram, Christian; Priyadarshi, Akshay Rai ...
2019 2nd International Conference on Signal Processing and Communication (ICSPC),
2019-March
Conference Proceeding
Creating content for games manually is very time consuming & labor-intensive work. With the constant evolution in hardware technology, it is difficult to cope up with the high levels of visual ...fidelity and performance that is expected of this medium. Procedural Content Generation is a very good alternative to manual content creation but still has seen very limited usage. Common drawbacks of this process are the lack of control over the output & and the absence of a unifying modeling framework to make use of these techniques, although more recent research has been aimed towards tackling this problem. This paper surveys the various properties of procedural terrain modeling techniques (which are: Random Number Generator, Perlin Noise, Voronoi Tessellation and Midpoint Displacement), assess the authenticity of the output and the control a user can exert over the procedure.
We predict that cyanoacetylene (HC\(_3\)N) is produced photochemically in the atmosphere of GJ 1132 b in abundances detectable by the James Webb Space Telescope (JWST), assuming that the atmosphere ...is hydrogen dominated and rich in molecular nitrogen (N\(_2\)), methane (CH\(_4\)) and hydrogen cyanide (HCN), as described by Swain et al. (2021). First, we construct line list and cross-sections for HC\(_3\)N. Then we apply these cross-sections and the model atmosphere of Swain et al. (2021) to a radiative transfer model in order to simulate the transmission spectrum of GJ 1132 b as it would be seen by JWST, accounting for the uncertainty in the retrieved abundances. We predict that cyanoacetylene features at various wavelengths, with a clear lone feature at 4.5 \(\mu\)m, observable by JWST after one transit. This feature persists within the \(1-\sigma\) uncertainty of the retrieved abundances of HCN and CH\(_4\). The signal is detectable for stratospheric temperatures \(\lesssim 600\) K and moderate stratospheric mixing (\(10^6 \, {\rm cm^2 \, s^{-1}} \lesssim K_{zz} \lesssim 10^8 \, {\rm cm^2 \, s^{-1}}\)). Our results also indicate that HC\(_3\)N is an important source of opacity that future retrieval models should consider.
Aim
Giant pituitary adenomas are difficult to resect due to multicompartmental extension. We developed a new grading system for giant pituitary adenomas (GPAs) considering possible extension in ...superior, lateral, anterior, and posterior (SLAP) directions. We also related the degree of resection to the SLAP grading.
Methods
A review of case files and radiological images of patients with the GPAs defined as pituitary adenomas with a size of more than 4 cm in any dimension was done. The extent of the tumour was noted and scored as per the SLAP system. The maximum total score is 10 and represents a large tumour with maximum extensions in all directions. The subtotal resection (STR) was defined as a residual tumour volume of more than 10%. The association between individual and total score on the degree of resection was determined.
Results
A total of 103 cases of GPAs were analyzed. All patients had a suprasellar (S) extension. The lateral (L) extension was seen in 97.3% of cases. The anterior (A) extension was seen in 28 (27.2%) cases. The posterior (P) extension was seen in 45 (43.7%). Forty-eight (46.6%) had a total score of 5 or more. The STR was achieved in 64 (62.2%) cases. On regression analysis, a total score of ≥5 was associated with odds of 5.02 (1.69-14.93), p-value 0.004 for STR.
Conclusion
The SLAP grading is a comprehensive grading system that can be applied easily to the GPAs and gives a complete picture of the extension of the tumour.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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