The mineral clouds on HD 209458b and HD 189733b Helling, Ch; Lee, G; Dobbs-Dixon, I ...
Monthly notices of the Royal Astronomical Society,
07/2016, Letnik:
460, Številka:
1
Journal Article
Recenzirano
Odprti dostop
3D atmosphere model results are used to comparatively study the kinetic, non-equilibrium cloud formation in the atmospheres of two example planets guided by the giant gas planets HD 209458b and ...HD 189733b. Rather independently of hydrodynamic model differences, our cloud modelling suggest that both planets are covered in mineral clouds throughout the entire modelling domain. Both planets harbour chemically complex clouds that are made of mineral particles that have a height-dependent material composition and size. The remaining gas-phase element abundances strongly affect the molecular abundances of the atmosphere in the cloud-forming regions. Hydrocarbon and cyanopolyyne molecules can be rather abundant in the inner, dense part of the atmospheres of HD 189733b and HD 209458b. No one value for metallicity and the C/O ratio can be used to describe an extrasolar planet. Our results concerning the presence and location of water in relation to the clouds explain some of the observed difference between the two planets. In HD 189733b, strong water features have been reported while such features appear less strong for HD 209458b. By considering the location of the clouds in the two atmospheres, we see that obscuring clouds exist high in the atmosphere of HD 209458b, but much deeper in HD 189733b. We further conclude that the (self-imposed) degeneracy of cloud parameters in retrieval methods can only be lifted if the cloud formation processes are accurately modelled in contrast to prescribing them by independent parameters.
Ultra-hot Jupiters (UHJs) are highly irradiated giant exoplanets with extremely high day-side temperatures, which lead to thermal dissociation of most molecular species. It is expected that the ...neutral hydrogen atom is one of the main species in the upper atmospheres of UHJs. Neutral hydrogen has been detected in several UHJs by observing their Balmer line absorption. In this work, we report four transit observations of the UHJ WASP-33b, performed with the CARMENES and HARPS-North spectrographs, and the detection of the H
α
, H
β
, and H
γ
lines in the planetary transmission spectrum. The combined H
α
transmission spectrum of the four transits has an absorption depth of 0.99 ± 0.05%, which corresponds to an effective radius of 1.31 ± 0.01
R
p
. The strong H
α
absorption indicates that the line probes the high-altitude thermosphere. We further fitted the three Balmer lines using the
PAWN
model, assuming that the atmosphere is hydrodynamic and in local thermodynamic equilibrium. We retrieved a thermosphere temperature 12 200
−1000
+1300
K and a mass-loss rate
Ṁ
= 1011.8
−0.5
+0.6
g s
−1
. The retrieved high mass-loss rate is compatible with the “Balmer-driven” atmospheric escape scenario, in which the stellar Balmer continua radiation in the near-ultraviolet is substantially absorbed by excited hydrogen atoms in the planetary thermosphere.
Context.
Theoretical studies predict the presence of thermal inversions in the atmosphere of highly irradiated gas giant planets. Recent observations have identified these inversion layers. However, ...the role of different chemical species in their formation remains unclear.
Aims.
We search for the signature of the thermal inversion agents TiO and Fe in the dayside emission spectrum of the ultra-hot Jupiter WASP-33b.
Methods.
The spectra were obtained with CARMENES and HARPS-N, covering different wavelength ranges. Telluric and stellar absorption lines were removed with
SYSREM
. We cross-correlated the residual spectra with model spectra to retrieve the signals from the planetary atmosphere.
Results.
We find evidence for TiO at a significance of 4.9σ with CARMENES. The strength of the TiO signal drops close to the secondary eclipse. No TiO signal is found with HARPS-N. An injection-recovery test suggests that the TiO signal is below the detection level at the wavelengths covered by HARPS-N. The emission signature of Fe is detected with both instruments at significance levels of 5.7σ and 4.5σ, respectively. By combining all observations, we obtain a significance level of 7.3σ for Fe. We find the TiO signal at
K
p
= 248.0
−2.5
+2.0
km s
−1
, which is in disagreement with the Fe detection at
K
p
= 225.0
−3.5
+4.0
km s
−1
. The
K
p
value for Fe is in agreement with prior investigations. The model spectra require different temperature profiles for TiO and Fe to match the observations. We observe a broader line profile for Fe than for TiO.
Conclusions.
Our results confirm the existence of a temperature inversion layer in the planetary atmosphere. The observed
K
p
offset and different strengths of broadening in the line profiles suggest the existence of a TiO-depleted hot spot in the planetary atmosphere.
Transport of pollution from remote sources into the state of Texas has been shown by modeling techniques, satellite, and in situ data. Attaining a better understanding of the impact (i.e., ...temporally) of remote pollution sources will provide a more robust/quantifiable basis for State Implementation Plans (SIPs) that govern air quality. Utilizing Tropospheric Emission Spectrometer (TES) and Ozone Monitoring Instrument (OMI) and in situ data for ozone (O
3
) and nitrogen dioxide (NO
2
) and Hybrid Single-Particle Lagrangian Integrated Trajectory Model (HYSPLIT), we assess whether high-pollution events in Texas are primarily sourced locally (i.e
.
, within Texas) or remotely. We focus on TES and OMI dates that exemplify high O
3
and NO
2
, over Texas’s lower troposphere from August 5, 2006, to June 21, 2009. For all dates and altitudes, 4-day back trajectory analyses, exemplified by high TES O
3
, show that remotely sourced from the Gulf of Mexico, Southeast USA, Midwest USA, Northeast USA, the Atlantic Ocean, Pacific Ocean, Mexico to Texas. The only exception is air at 1 km on July 22, 2006, which shows that air at this altitude is sourced within Texas. Throughout half of the eastern portion of Texas, TES shows O
3
enhancements in the boundary layer and OMI shows O
3
and NO
2
enhancements via tropospheric column profiles (O
3
between 75 and 90 ppbv; NO
2
≥5.5 molecules cm
−2
). These enhancements complement the HYSPLIT 4-day trajectory analyses, which gives further indication that they are influenced by transport from remote sources. Dates with co-located satellite and in situ data (e.g
.
, August 2, 2005) further exemplify the need to consider satellite and in situ data and modeling data/forecasts when creating SIPs for compliance with Environmental Protection Agency and the Texas Commission on Environmental Quality air quality standards. Despite the fact that quantifying local versus remote sources is in its early stages, Texas has become increasingly compliant with Environmental Protection Agency (EPA) regulations. Environmental Systems Research Institute’s ArcGIS exemplifies the noticeable decrease in the number of days that locales in Texas exceed EPA’s limit for O
3
. From 2005 to 2009, population standard deviation and standard error of the mean, and true sample deviation of the sample mean for O
3
and NO
2
, at all 16 monitoring sites distributed throughout Texas, are temporally consistent and small—reinforcing the reliability of in situ data as they are consistent throughout. This investigation has global implications for regions within countries that enforce air quality mandates. Such governing bodies should consider utilizing data assimilation (of in situ data) for air quality prediction as a part of the governmental process that produces such laws. This could potentially keep regions more accountable for emissions both locally and far from high source points.
Context.
The CARMENES instrument, installed at the 3.5 m telescope of the Calar Alto Observatory in Almería, Spain, was conceived to deliver high-accuracy radial velocity (RV) measurements with ...long-term stability to search for temperate rocky planets around a sample of nearby cool stars. Moreover, the broad wavelength coverage was designed to provide a range of stellar activity indicators to assess the nature of potential RV signals and to provide valuable spectral information to help characterise the stellar targets.
Aims.
We describe the CARMENES guaranteed time observations (GTO), spanning from 2016 to 2020, during which 19 633 spectra for a sample of 362 targets were collected. We present the CARMENES Data Release 1 (DR1), which makes public all observations obtained during the GTO of the CARMENES survey.
Methods.
The CARMENES survey target selection was aimed at minimising biases, and about 70% of all known M dwarfs within 10 pc and accessible from Calar Alto were included. The data were pipeline-processed, and high-level data products, including 18 642 precise RVs for 345 targets, were derived. Time series data of spectroscopic activity indicators were also obtained.
Results.
We discuss the characteristics of the CARMENES data, the statistical properties of the stellar sample, and the spectroscopic measurements. We show examples of the use of CARMENES data and provide a contextual view of the exoplanet population revealed by the survey, including 33 new planets, 17 re-analysed planets, and 26 confirmed planets from transiting candidate follow-up. A subsample of 238 targets was used to derive updated planet occurrence rates, yielding an overall average of 1.44 ± 0.20 planets with 1
M
⊕
<
M
pl
sin
i <
1000
M
⊕
and 1 day <
P
orb
< 1000 days per star, and indicating that nearly every M dwarf hosts at least one planet. All the DR1 raw data, pipeline-processed data, and high-level data products are publicly available online.
Conclusions.
CARMENES data have proven very useful for identifying and measuring planetary companions. They are also suitable for a variety of additional applications, such as the determination of stellar fundamental and atmospheric properties, the characterisation of stellar activity, and the study of exoplanet atmospheres.
The CARMENES instrument was conceived to deliver high-accuracy radial velocity (RV) measurements with long-term stability to search for temperate rocky planets around a sample of nearby cool stars. ...The broad wavelength coverage was designed to provide a range of stellar activity indicators to assess the nature of potential RV signals and to provide valuable spectral information to help characterise the stellar targets. The CARMENES Data Release 1 (DR1) makes public all observations obtained during the CARMENES guaranteed time observations, which ran from 2016 to 2020 and collected 19,633 spectra for a sample of 362 targets. The CARMENES survey target selection was aimed at minimising biases, and about 70% of all known M dwarfs within 10 pc and accessible from Calar Alto were included. The data were pipeline-processed, and high-level data products, including 18,642 precise RVs for 345 targets, were derived. Time series data of spectroscopic activity indicators were also obtained. We discuss the characteristics of the CARMENES data, the statistical properties of the stellar sample, and the spectroscopic measurements. We show examples of the use of CARMENES data and provide a contextual view of the exoplanet population revealed by the survey, including 33 new planets, 17 re-analysed planets, and 26 confirmed planets from transiting candidate follow-up. A subsample of 238 targets was used to derive updated planet occurrence rates, yielding an overall average of 1.44+/-0.20 planets with 1 M_Earth < M sin i < 1000 M_Earth and 1 d < P_orb < 1000 d per star, and indicating that nearly every M dwarf hosts at least one planet. CARMENES data have proven very useful for identifying and measuring planetary companions as well as for additional applications, such as the determination of stellar properties, the characterisation of stellar activity, and the study of exoplanet atmospheres.
Theoretical studies predict the presence of thermal inversions in the atmosphere of highly irradiated gas giant planets. Recent observations have identified these inversion layers. However, the role ...of different chemical species in their formation remains unclear. We search for the signature of the thermal inversion agents TiO and Fe in the dayside emission spectrum of the ultra-hot Jupiter WASP-33b. The spectra were obtained with CARMENES and HARPS-N, covering different wavelength ranges. Telluric and stellar absorption lines were removed with SYSREM. We cross-correlated the residual spectra with model spectra to retrieve the signals from the planetary atmosphere. We find evidence for TiO at a significance of 4.9\(\mathrm{\sigma}\) with CARMENES. The strength of the TiO signal drops close to the secondary eclipse. No TiO signal is found with HARPS-N. An injection-recovery test suggests that the TiO signal is below the detection level at the wavelengths covered by HARPS-N. The emission signature of Fe is detected with both instruments at significance levels of 5.7\(\mathrm{\sigma}\) and 4.5\(\mathrm{\sigma}\), respectively. By combining all observations, we obtain a significance level of 7.3\(\mathrm{\sigma}\) for Fe. We find the TiO signal at \(K_\mathrm{p}\) = \(248.0_{-2.5}^{+2.0}\) km s\(^{-1}\), which is in disagreement with the Fe detection at \(K_\mathrm{p}\) = \(225.0_{-3.5}^{+4.0}\) km s\(^{-1}\). The \(K_\mathrm{p}\) value for Fe is in agreement with prior investigations. The model spectra require different temperature profiles for TiO and Fe to match the observations. We observe a broader line profile for Fe than for TiO. Our results confirm the existence of a temperature inversion layer in the planetary atmosphere. The observed \(K_\mathrm{p}\) offset and different strengths of broadening in the line profiles suggest the existence of a TiO-depleted hot spot in the planetary atmosphere.
Ultra-hot Jupiters (UHJs) are highly irradiated giant exoplanets with extremely high day-side temperatures, which lead to thermal dissociation of most of the molecular species. It is expected that ...the neutral hydrogen atom is one of the main species in the upper atmospheres of ultra-hot Jupiters. Neutral hydrogen has been detected in several UHJs by observing its Balmer line absorption. Here, we report four transit observations of the ultra-hot Jupiter WASP-33b, performed with the CARMENES and HARPS-North spectrographs, and the detection of the H\({\alpha}\), H\({\beta}\), and H\({\gamma}\) lines in the planetary transmission spectrum. The combined H\(\alpha\) transmission spectrum of the four transits has an absorption depth of 0.99\(\pm\)0.05 %, which corresponds to an effective radius of 1.31\(\pm\)0.01 Rp . The strong H\({\alpha}\) absorption indicates that the line probes the high-altitude thermosphere. We further fitted the three Balmer lines using the PAWN model, assuming that the atmosphere is hydrodynamic and in LTE. We retrieved a thermosphere temperature \(12200^{+1300}_{-1000}\) K and a mass-loss rate \({\rm \dot{M}}=10^{11.8^{+0.6}_{-0.5}}\) g/s. The retrieved large mass-loss rate is compatible with the "Balmer-driven" atmospheric escape scenario, in which the stellar Balmer continua radiation in the near-ultraviolet is substantially absorbed by the excited hydrogen atoms in the planetary thermosphere.
3D atmosphere model results are used to comparatively study the kinetic, non-equilibrium cloud formation in the atmospheres of two example planets guided by the giant gas planets HD209458b and ...HD189733b. Rather independently of hydrodynamic model differences, our cloud modelling suggests that both planets are covered in mineral clouds throughout the entire modelling domain. Both planets harbour chemically complex clouds that are made of mineral particles that have a height-dependent material composition and size. The remaining gas-phase element abundances strongly effects the molecular abundances of the atmosphere in the cloud forming regions. Hydrocarbon and cyanopolyyne molecules can be rather abundant in the inner, dense part of the atmospheres of HD189733b and HD209458b. No one value for metallicity and the C/O ratio can be used to describe an extrasolar planet. Our results concerning the presence and location of water in relation to the clouds explain some of the observed differences between the two planets. In HD189733b, strong water features have been reported while such features appear less strong for HD209458b. By considering the location of the clouds in the two atmospheres, we see that obscuring clouds exist high in the atmosphere of HD209458b, but much deeper in HD189733b. We further conclude that the (self-imposed) degeneracy of cloud parameters in retrieval methods can only be lifted if the cloud formation processes are accurately modelled in contrast to prescribing them by independent parameters.
Mouse strain differences for intake of sucrose and saccharin have been reported across studies, and some of these differences have been related to variants of the
Tas1r3 taste receptor gene. However, ...several methodological concerns remain, including use of relatively few strains and/or a limited number of palatable concentrations in previous analyses. The present study examined strain differences in sucrose intake among 11 inbred (A/J, AKR/J, BALB/cJ, CBA/J, C3H/HeJ, C57BL6/J, C57BL10/J, DBA/2J, SJL/J, SWR/J, 129P3/J) and one outbred (CD-1) mouse strains across nine different sucrose concentrations (0.0001–20%) using two-bottle 24-h preference tests which controlled for sucrose concentration presentation effects, sucrose and water bottle positions, and measurement of kilocalorie intake as sucrose or chow. A/J, C57BL/6J, CD-1 and SWR/J strains consumed the greatest (11.6–22 ml) amount of sucrose, whereas the A/J, C57BL/10J, SJL/J and SWR/J strains consumed the greatest (44–56%) percentages of kilocalories as sucrose. The AKR/J, CBA/J, C3H/HeJ and DBA/2J strains consumed the least (6.9–7.9 ml) amount of sucrose, and displayed lower (20–30%) percentages of kilocalories consumed as sucrose. Whereas A/J, C57BL/6J, C57BL/10J, CD-1, SWR/J and SJL/J strains all displayed the most pronounced compensatory decreases in chow intake as the percentage of kilocalories consumed as sucrose increased, the AKR/J, C3H/HeJ and DBA/2J strains failed to significantly alter chow intake even at high sucrose concentrations. There was a paucity of significant correlations in the percentage of sucrose intake between sucrose concentrations, but percentage of sucrose intake at lower concentrations did correlate with previous descriptions of saccharin intake and variants of the
Tas1r3 taste receptor gene. These data demonstrate clear mouse strain differences across a range of measures in sucrose intake across a wide range of concentrations, but caution against extrapolating between extremely high and low concentrations. The identification of strains with diverging abilities to regulate kilocalorie intake when presented with high sucrose concentrations may lead to the successful QTL mapping of this trait.
PDF
