Showing papers by "Michael Meyer published in 2020"

The SPHERE infrared survey for exoplanets (SHINE). III. The demographics of young giant exoplanets below 300 au with SPHERE

Abstract: The SHINE project is a 500-star survey performed with SPHERE on the VLT for the purpose of directly detecting new substellar companions and understanding their formation and early evolution. Here we present an initial statistical analysis for a subsample of 150 stars that are representative of the full SHINE sample. Our goal is to constrain the frequency of substellar companions with masses between 1 and 75 MJup and semimajor axes between 5 and 300 au. We adopt detection limits as a function of angular separation from the survey data for all stars converted into mass and projected orbital separation using the BEX-COND-hot evolutionary tracks and known distance to each system. Based on the results obtained for each star and on the 13 detections in the sample, we use a MCMC tool to compare our observations to two different types of models. The first is a parametric model based on observational constraints, and the second type are numerical models that combine advanced core accretion and gravitational instability planet population synthesis. Using the parametric model, we show that the frequencies of systems with at least one substellar companion are $23.0_{-9.7}^{+13.5}\%$, $5.8_{-2.8}^{+4.7}\%$, and $12.6_{-7.1}^{+12.9}\%$ for BA, FGK, and M stars, respectively. We also demonstrate that a planet-like formation pathway probably dominates the mass range from 1-75 MJup for companions around BA stars, while for M dwarfs, brown dwarf binaries dominate detections. In contrast, a combination of binary star-like and planet-like formation is required to best fit the observations for FGK stars. Using our population model and restricting our sample to FGK stars, we derive a frequency of $5.7_{-2.8}^{+3.8}\%$, consistent with predictions from the parametric model. More generally, the frequency values that we derive are in excellent agreement with values obtained in previous studies.

MIRACLES: atmospheric characterization of directly imaged planets and substellar companions at 4–5 μm - I. Photometric analysis of β Pic b, HIP 65426 b, PZ Tel B, and HD 206893 B

Abstract: Context. Directly imaged planets and substellar companions are key targets for the characterization of self-luminous atmospheres. Their photometric appearance at 4–5 μ m is sensitive to the chemical composition and cloud content of their atmosphere.Aims. We aim to systematically characterize the atmospheres of directly imaged low-mass companions at 4–5 μ m. We want to homogeneously process the data, provide robust flux measurements, and compile a photometric library at thermal wavelengths of these mostly young, low-gravity objects. In this way, we want to find trends related to their spectral type and surface gravity by comparing with isolated brown dwarfs and predictions from atmospheric models.Methods. We used the high-resolution, high-contrast capabilities of NACO at the Very Large Telescope (VLT) to directly image the companions of HIP 65426, PZ Tel, and HD 206893 in the NB4.05 and/or M ′ filters. For the same targets, and additionally β Pic, we also analyzed six archival VLT/NACO datasets which were taken with the NB3.74, L ′, NB4.05, and M ′ filters. The data processing and photometric extraction of the companions was done with PynPoint while the species toolkit was used to further analyze and interpret the fluxes and colors.Results. We detect for the first time HIP 65426 b, PZ Tel B, and HD 206893 B in the NB4.05 filter, PZ Tel B and HD 206893 B in the M ′ filter, and β Pic b in the NB3.74 filter. We provide calibrated magnitudes and fluxes with a careful analysis of the error budget, both for the new and archival datasets. The L ′–NB4.05 and L ′–M ′ colors of the studied sample are all red while the NB4.05–M ′ color is blue for β Pic b, gray for PZ Tel B, and red for HIP 65426 b and HD 206893 B (although typically with low significance). The absolute NB4.05 and M ′ fluxes of our sample are all larger than those of field dwarfs with similar spectral types. Finally, the surface gravity of β Pic b has been constrained to dex from its photometry and dynamical mass.Conclusions. A red color at 3–4 μ m and a blue color at 4–5 μ m might be (partially) caused by H2 O and CO absorption, respectively, which are expected to be the most dominant gaseous opacities in hot (T eff ≳ 1300 K) atmospheres. The red characteristics of β Pic b, HIP 65426 b, and HD 206893 B at 3–5μ m, as well as their higher fluxes in NB4.05 and M ′ compared to field dwarfs, indicate that cloud densities are enhanced close to the photosphere as a result of their low surface gravity.

Protoplanetary disk masses in NGC 2024: Evidence for two populations

Abstract: Context. Protoplanetary disks in dense, massive star-forming regions are strongly affected by their environment. How this environmental impact changes over time is an important constraint on disk evolution and external photoevaporation models.Aims. We characterize the dust emission from 179 disks in the core of the young (0.5 Myr) NGC 2024 cluster. By studying how the disk mass varies within the cluster, and comparing these disks to those in other regions, we aim to determine how external photoevaporation influences disk properties over time.Methods. Using the Atacama Large Millimeter/submillimeter Array, a 2.9′× 2.9′ mosaic centered on NGC 2024 FIR 3 was observed at 225 GHz with a resolution of 0.25″, or ~100 AU. The imaged region contains 179 disks identified at IR wavelengths, seven new disk candidates, and several protostars.Results. The overall detection rate of disks is 32 ± 4%. Few of the disks are resolved, with the exception of a giant (R = 300 AU) transition disk. Serendipitously, we observe a millimeter flare from an X-ray bright young stellar object (YSO), and resolve continuum emission from a Class 0 YSO in the FIR 3 core. Two distinct disk populations are present: a more massive one in the east, along the dense molecular ridge hosting the FIR 1-5 YSOs, with a detection rate of 45 ± 7%. In the western population, towards IRS 1, only 15 ± 4% of disks are detected.Conclusions. NGC 2024 hosts two distinct disk populations. Disks along the dense molecular ridge are young (0.2–0.5 Myr) and partly shielded from the far ultraviolet radiation of IRS 2b; their masses are similar to isolated 1–3 Myr old SFRs. The western population is older and at lower extinctions, and may be affected by external photoevaporation from both IRS 1 and IRS 2b. However, it is possible these disks had lower masses to begin with.

Protoplanetary disk masses in NGC 2024: Evidence for two populations.

Abstract: Protoplanetary disks in dense, massive star-forming regions are strongly affected by their environment. How this environmental impact changes over time is an important constraint on disk evolution and external photoevaporation models. We characterize the dust emission from 179 disks in the core of the young (0.5 Myr) NGC 2024 cluster. By studying how the disk mass varies within the cluster, and comparing these disks to those in other regions, we aim to determine how external photoevaporation influences disk properties over time. Using the Atacama Large Millimeter/submillimeter Array, a 2.9' x 2.9' mosaic centered on NGC 2024 FIR 3 was observed at 225 GHz with a resolution of 0.25'', or ~100 AU. The imaged region contains 179 disks identified at IR wavelengths, seven new disk candidates, and several protostars. The overall detection rate of disks is $32 \pm 4\%$. Few of the disks are resolved, with the exception of a giant (R = 300 AU) transition disk. Serendipitously, we observe a millimeter flare from an X-ray bright young stellar object (YSO), and resolve continuum emission from a Class 0 YSO in the FIR 3 core. Two distinct disk populations are present: a more massive one in the east, along the dense molecular ridge hosting the FIR 1-5 YSOs, with a detection rate of $45 \pm 7\%$. In the western population, towards IRS 1, only $15 \pm 4\%$ of disks are detected. NGC 2024 hosts two distinct disk populations. Disks along the dense molecular ridge are young (0.2 - 0.5 Myr) and partly shielded from the far ultraviolet radiation of IRS 2b; their masses are similar to isolated 1 - 3 Myr old SFRs. The western population is older and at lower extinctions, and may be affected by external photoevaporation from both IRS 1 and IRS 2b. However, it is possible these disks had lower masses to begin with.

New Method for Measuring Angle-Resolved Phases in Photoemission

Abstract: Quantum mechanically, photoionization can be fully described by the complex photoionization amplitudes that describe the transition between the ground state and the continuum state. Knowledge of the value of the phase of these amplitudes has been a central interest in photoionization studies and newly developing attosecond science, since the phase can reveal important information about phenomena such as electron correlation. We present a new attosecond-precision interferometric method of angle-resolved measurement for the phase of the photoionization amplitudes, using two phase-locked Extreme Ultraviolet pulses of frequency ω and 2ω, from a Free-Electron Laser. Phase differences ∆η̃ between oneand two-photon ionization channels, averaged over multiple wave packets, are extracted for neon 2p electrons as a function of emission angle at photoelectron energies 7.9, 10.2, and 16.6 eV. ∆η̃ is nearly constant for emission parallel to the electric vector but increases at 10.2 eV for emission perpendicular to the electric vector. We model our observations with both perturbation and ab initio theory, and find excellent agreement. In the existing method for attosecond measurement, Reconstruction of Attosecond Beating By Interference of Two-photon Transitions (RABBITT), a phase difference between two-photon pathways involving absorption and emission of an infrared photon is extracted. Our method can be used for extraction of a phase difference between single-photon and two-photon pathways and provides a new tool for attosecond science, which is complementary to RABBITT. ∗ corresponding author; kiyoshi.ueda@tohoku.ac.jp † Now at LIDYL, CEA, CNRS, Université Paris-Saclay, CEA-Saclay, 91191 Gif-sur-Yvette, France. ‡ corresponding author; prince@elettra.eu

Opportunities for two-color experiments in the soft X-ray regime at the European XFEL

Abstract: X-ray pump/X-ray probe applications are made possible at X-ray Free Electron Laser (XFEL) facilities by generating two X-ray pulses with different wavelengths and controllable temporal delay. In order to enable this capability at the European XFEL, an upgrade project to equip the soft X-ray SASE3 beamline with a magnetic chicane is underway. In the present paper we describe the status of the project, its scientific focus and expected performance, including start-to-end simulations of the photon beam transport up to the sample, as well as recent experimental results demonstrating two-color lasing at photon energies of 805 eV + 835 eV and 910 eV + 950 eV. Additionally, we discuss methods to analyze the spectral properties and the intensity of the generated radiation to provide on-line diagnostics for future user experiments.

The Evolution of Disk Winds from a Combined Study of Optical and Infrared Forbidden Lines

Abstract: We analyze high-resolution (dv= 10$^{-8}$ Msun/yr) while LVCs are found in sources with low Macc, low [OI] luminosity, and large infrared spectral index (n13-31). Interestingly, the [NeII] and [OI] LVC luminosities display an opposite behaviour with n13-31: as the inner dust disk depletes (higher n13-31) the [NeII] luminosity increases while the [OI] weakens. The [NeII] and [OI] HVC profiles are generally similar with centroids and FWHMs showing the expected behaviour from shocked gas in micro-jets. In contrast, the [NeII] LVC profiles are typically more blueshifted and narrower than the [OI] profiles. The FWHM and centroid vs. disk inclination suggest that the [NeII] LVC predominantly traces unbound gas from a slow, wide-angle wind that has not lost completely the Keplerian signature from its launching region. We sketch an evolutionary scenario that could explain the combined [OI] and [NeII] results and includes screening of hard (~1keV) X-rays in inner, mostly molecular, MHD winds.

Recurrent horizontal transfer identifies mitochondrial positive selection in a transmissible cancer

Abstract: Autonomous replication and segregation of mitochondrial DNA (mtDNA) creates the potential for evolutionary conflict driven by emergence of haplotypes under positive selection for 'selfish' traits, such as replicative advantage. However, few cases of this phenomenon arising within natural populations have been described. Here, we survey the frequency of mtDNA horizontal transfer within the canine transmissible venereal tumour (CTVT), a contagious cancer clone that occasionally acquires mtDNA from its hosts. Remarkably, one canine mtDNA haplotype, A1d1a, has repeatedly and recently colonised CTVT cells, recurrently replacing incumbent CTVT haplotypes. An A1d1a control region polymorphism predicted to influence transcription is fixed in the products of an A1d1a recombination event and occurs somatically on other CTVT mtDNA backgrounds. We present a model whereby 'selfish' positive selection acting on a regulatory variant drives repeated fixation of A1d1a within CTVT cells.

RefPlanets: Search for reflected light from extrasolar planets with SPHERE/ZIMPOL

Abstract: Swiss National Science Foundation (SNSF): 200020_162630/1. ESO. Centre National de la Recherche Scientifique (CNRS). MPIA (Germany). Istituto Nazionale Astrofisica. FINES (Switzerland). NOVA (Netherlands). European Commission Joint Research Centre: RII3-Ct-2004-001566, 226604, 312430. Programme National de Planetologie (PNP) of CNRS-INSU in France. Programme National de Physique Stellaire (PNPS) of CNRS-INSU in France. French National Research Agency (ANR): ANR10 LABX56. Centre National de la Recherche Scientifique (CNRS). French National Research Agency (ANR): ANR-14-CE330018. Swiss National Science Foundation (SNSF). French National Research Agency (ANR): ANR10 LABX56. Ministry of Education, Universities and Research (MIUR). Research Projects of National Relevance (PRIN). INAF/Frontiera of the Italian Ministry of Education, University, and Research. European Research Council under the Horizon 2020 Framework Program via the ERC Advanced Grant Origins: 83 24 28.

PSI ‘Neutron Microscope’ at ILL-D50 beamline – first results

Abstract: A high-resolution neutron imaging system referred to as ‘Neutron Microscope’ (NM) has been recently established as a piece of instrumental equipment at the Paul Scherrer Institut (PSI), Switzerland. It is providing the wide user community of the Neutron Imaging and Applied Materials Group (NIAG) with the capability of spatial image resolution below 5 μm at effective pixel sizes of 1.3 μm. The NM has been designed as a portable, self-contained system that can be moved between beamlines at PSI with only moderate effort. In this contribution, we report on the first results and experience with the Neutron Microscope externally, at a beamline of another neutron source outside the Swiss Spallation Neutron Source (SINQ). In June 2018, NM has been transported to the Institute Laue-Langevin (ILL) and was successfully installed at the D50 beamline for four days. A gadolinium based Siemens star produced at PSI has been used for the assessment of the spatial resolution. The spatial resolution achieved using the Neutron Microscope at ILL-D50 equalled 4.5 μm. Above that, several high-resolution tomographies of various samples were acquired, of which an illustrative example is presented. Introduction High spatial resolution neutron imaging is a fast developing area driven by the demands from the user community (for example that of electrochemistry [1]). Provided that ‘high resolution neutron imaging’ is loosely defined as neutron imaging with the capability to resolve about 10 μm structures or better, there are several approaches that demonstrate such capability [2],[3],[4],[5],[6],[7]. At PSI, high resolution neutron imaging has been advanced with the project ‘Neutron Microscope’. In this project, a detector based on a high-numerical aperture objective [8] combined with very thin, though efficient, isotopically-enriched 157-gadolinium oxysulfide scintillator screens [9] was developed and led to the achievement of about five μm isotropic spatial resolution in 2D [10]. Despite these clear advances in the field of the high spatial resolution neutron imaging detectors, it is the available flux (even at rather powerful neutron sources) that sets limitations on both the achievable resolution and the performable experiments. Grosse & Kardjilov [11] have recently proposed a useful theoretical model that estimates the time necessary for neutron radiography/tomography to reveal unambiguously structures with a given contrast at a specific required spatial resolution. Even though the model seems to provide a conservative estimate [12], it is clear that -for certain contrast conditionsneutron tomography of very high spatial resolution requires prohibitively long exposure times even at sources as powerful as SINQ, PSI. Neutron Radiography WCNR-11 Materials Research Forum LLC Materials Research Proceedings 15 (2020) 23-28 https://doi.org/10.21741/9781644900574-4 24 Even for favourable contrast conditions, such as in the case of the neutron tomography of a small porous gold sample [13], the exposure times of several days are required at BOA beamline [14] to achieve approximately 10 μm true spatial resolution in 3D. It is therefore clear that the high spatial resolution neutron imaging applications are bound to seek the highest neutron flux sources. As the NM has been designed as self-contained detector that can be transported between the beamlines at PSI with only moderate effort, it can also be moved to other neutron sources. Because the neutron source of ILL provides outstanding neutron flux conditions, the NM detector system was transferred recently from PSI to the D50 beamline [15] at ILL and its performance under cutting edge flux conditions has been tested With an estimated neutron flux of 6 × 10 n/cms, the D50 beamline provides currently the highest available flux of cold neutrons for imaging applications. In the following we provide some results of this initial campaign. Installation of NM at ILL-D50 The entire ‘Neutron Microscope’ instrumentation has been transported to and installed at ILL within one day. The NM has been installed at the most downstream position inside the current D50 beamline bunker (as shown in Figures 1a and 1b). Figure 1 – PSI ‘Neutron Microscope’ at ILL-D50 beamline: (a) being installed through the open roof into the bunker, (b) positioned at the most downstream position of the ILL-D50, (c) fitted with B4C sheets and other borated shielding materials. The red dashed arrow in Figure 2b indicates the neutron beam. It is worth noting that the installation had, despite the independent control of the system, taken only about 6 hours, after which the NM was ready for the first images to be acquired. A significant part of the installation time has been spent on fitting the NM with shielding material (see Figure 1c) in order to avoid activation. The scintillator screen of the NM has been positioned at 11.13 m downstream the 30 mm-diameter pinhole, thus providing collimation ratio Neutron Radiography WCNR-11 Materials Research Forum LLC Materials Research Proceedings 15 (2020) 23-28 https://doi.org/10.21741/9781644900574-4 25 of 371. In the next step of the installation, the NM has been focused using a standard resolution test object a gadolinium-based Siemens star [16]. The focusing procedure was relatively quick again due to the superior neutron flux. Results In the first experiment, to establish the resolution capability achieved, eighty images of the Siemens star pattern, fifty open beam images and ten dark current images were acquired. All images were recorded with 30 seconds exposure time and the test object was positioned in the close vicinity of the scintillator screen (scintillator-sample distance smaller than 0.5 mm). The scintillator was an approximately 3.5 micrometres thick Gd isotopically-enriched gadolinium oxysulfide screen. The substrate of the screen consisted of a silicon wafer coated with a 200-nm iridium layer for light output enhancement [17]. The images were acquired using a sCMOS camera (Hamamatsu ORCA Flash 4.0, pixel size 6.5 μm). Thanks to the 5-fold magnification of the NM optics, the pixel size (pixel resolution) of the acquired images was equal to 1.3 micrometers. Two separate open-beam corrected images based on 40 individual radiographs of the test object each were created. These were used for Fourier ring correlation and for the visual inspection of the achieved spatial resolution. One of these images is shown in Figure 2 (left) while the right hand side image presents an enlarged image of the Siemens star centre. Figure 2 – (left) Neutron radiography of a Gd based Siemens star, (right) close-up of the centre of the Siemens star of the left hand side image clearly revealing the ends of the individual 4.5 micrometres spokes. It is clearly visible that the thinnest ends of the individual spokes of the Siemens star can be resolved in the image, in particular in the magnified detail on the right hand side of Fig. 2. The size of the thinnest spokes is equal to 4.5 μm (line pair: 9 μm). For the quantitative analyses, Fourier ring correlation [18] was applied to the Siemens star images and resulted in a measured spatial resolution of 4.2 μm. Subsequently, after assessing the resolution experimentally, several small static samples were tomographed. The tomographed samples included pieces of Zircaloy nuclear fuel cladding [19], bits of additively manufactured gold alloys, and a cylinder of a diameter of approximately 2.5 mm of a gold-lead alloy. Neutron Radiography WCNR-11 Materials Research Forum LLC Materials Research Proceedings 15 (2020) 23-28 https://doi.org/10.21741/9781644900574-4 26 Figure 3 – Example of a neutron microtomography using the PSI ’Neutron Microscope’ at the ILL-D50 beamline: A vertical slice from a neutron microtomography dataset showing dendritic microstructures of lead, voids and gold in a sample of a gold-lead alloy. The detailed description of the results of these neutron microtomographies goes beyond the purpose and the scope of this paper. However, Figure 3 provides an example of the high quality of the resulting datasets showing a randomly chosen vertical slice from the microtomographic dataset revealing in detail the dendritic microstructure of lead in a gold-lead alloy [20] with unprecedented spatial resolution. From the point of view of the temporal resolution, the presented lead-gold alloy microtomography required approximately 12 hours of beamtime only including the acquisition of open beam, dark current and black body [21] images. Discussion & Outlook From the practical and logistic point of view, the installation of NM at ILL was a rather swift procedure. One of the issues that need to be addressed when using a detector at another neutron facility is the activation of the system. Naturally, the pieces of NM that were exposed to the direct beam (i.e. scintillator screen/holder and the mirror) were expected to be activated beyond a level for immediate release. However, readily available duplicates of these pieces enable transfer and usability of the system elsewhere within about 24-48 hours. Despite taking care with shielding the NM from any unnecessary other neutrons, few parts of the rest of the instrumentation were very slightly activated (likely due to neutrons scattered from Neutron Radiography WCNR-11 Materials Research Forum LLC Materials Research Proceedings 15 (2020) 23-28 https://doi.org/10.21741/9781644900574-4 27 the sample/scintillator/mirror) at the end of the campaign (~0.15 μSv/h). This activation led to the necessity to prolong the stay of NM at ILL for another 24 hours. The procurement of more efficient shielding for NM can alleviate this situation in the future. Regarding the results themselves, it was shown that the favourable combination of NM with the superior flux at ILL-D50 can provide highest spatial resolution and quality of neutron imaging data both in 2D and in 3D with significantly reduced exposure times and hence higher efficiency

Antagonism of interferon signaling by fibroblast growth factors promotes viral replication.

Abstract: Fibroblast growth factors (FGFs) play key roles in the pathogenesis of different human diseases, but the cross-talk between FGFs and other cytokines remains largely unexplored. We identified an unexpected antagonistic effect of FGFs on the interferon (IFN) signaling pathway. Genetic or pharmacological inhibition of FGF receptor signaling in keratinocytes promoted the expression of interferon-stimulated genes (ISG) and proteins in vitro and in vivo. Conversely, FGF7 or FGF10 treatment of keratinocytes suppressed ISG expression under homeostatic conditions and in response to IFN or poly(I:C) treatment. FGF-mediated ISG suppression was independent of IFN receptors, occurred at the transcriptional level, and required FGF receptor kinase and proteasomal activity. It is not restricted to keratinocytes and functionally relevant, since FGFs promoted the replication of herpes simplex virus I (HSV-1), lymphocytic choriomeningitis virus, and Zika virus. Most importantly, inhibition of FGFR signaling blocked HSV-1 replication in cultured human keratinocytes and in mice. These results suggest the use of FGFR kinase inhibitors for the treatment of viral infections.

The evolution of disk winds from a combined study of optical and infrared forbidden lines

Abstract: We analyze high-resolution (Δv ≤ 10 km s⁻¹) optical and infrared spectra covering the [O I] λ6300 and [Ne II] 12.81 μm lines from a sample of 31 disks in different evolutionary stages. Following work at optical wavelengths, we use Gaussian profiles to fit the [Ne II] lines and classify them into high-velocity component (HVC) or low-velocity component (LVC) if the line centroid is more or less blueshifted than 30 km s⁻¹ with respect to the stellar radial velocity, respectively. Unlike for the [O I], where an HVC is often accompanied by an LVC, all 17 sources with an [Ne II] detection have either an HVC or an LVC. [Ne II] HVCs are preferentially detected toward high accretors (M_(acc) > 10⁻⁸M_⊙ yr⁻¹), while LVCs are found in sources with low M_(acc), low [O I] luminosity, and large infrared spectral index (n₁₃₋₃₁). Interestingly, the [Ne II] and [O I] LVC luminosities display an opposite behavior with n₁₃₋₃₁: as the inner dust disk depletes (higher n₁₃₋₃₁), the [Ne II] luminosity increases while the [O I] weakens. The [Ne II] and [O I] HVC profiles are generally similar, with centroids and FWHMs showing the expected behavior from shocked gas in microjets. In contrast, the [Ne II] LVC profiles are typically more blueshifted and narrower than the [O I] profiles. The FWHM and centroid versus disk inclination suggest that the [Ne II] LVC predominantly traces unbound gas from a slow, wide-angle wind that has not lost completely the Keplerian signature from its launching region. We sketch an evolutionary scenario that could explain the combined [O I] and [Ne II] results and includes screening of hard (~1 keV) X-rays in inner, mostly molecular, MHD winds.

The search for disks or planetary objects around directly imaged companions: A candidate around DH Tauri B

Abstract: ESO Centre National de la Recherche Scientifique (CNRS) MPIA (Germany) Istituto Nazionale Astrofisica (INAF) FINES (Switzerland) NOVA (Netherlands) European Commission Sixth and Seventh Framework Programmes as part of the Optical Infrared Coordination Network for Astronomy (OPTICON) RII3-Ct-2004-001566 226604 312430 Ministry of Education, Universities and Research (MIUR) Comision Nacional de Investigacion Cientifica y Tecnologica (CONICYT) CONICYT FONDECYT 11190837 Programme National de Planetologie (PNP) Programme National de Physique Stellaire (PNPS) of CNRS-INSU French National Research Agency (ANR) ANR10 LABX56 Centre National de la Recherche Scientifique (CNRS) European Commission French National Research Agency (ANR) European Commission Ministry of Education, Universities and Research (MIUR) Istituto Nazionale Astrofisica (INAF) Research Projects of National Relevance (PRIN) LBTI team European Research Council under the Horizon 2020 Framework Program via the ERC Advanced Grant Origins 83 24 28

The Demographics of Exoplanets

Abstract: In the broadest sense, the primary goal of exoplanet demographic surveys is to determine the frequency and distribution of planets as a function of as many of the physical parameters that may influence planet formation and evolution as possible, over as broad of a range of these parameters as possible. Empirically-determined exoplanet demographics provide the ground truth that all planet formation and evolution theories must reproduce. By comparing these planet distributions to the predictions of planet formation theories, we can begin to both test and refine these theories. In this chapter, we review the major results on exoplanet demographics to date. In this context, we identify a set of important open questions that remain to be answered. We outline the challenges of measuring the demographics of exoplanets using the variety of detection methods at our disposal. Finally, we summarize some of the future opportunities for refining and expanding our understanding of exoplanet demographics.

Mouse genetics identifies unique and overlapping functions of fibroblast growth factor receptors in keratinocytes.

Abstract: Fibroblast growth factors (FGFs) are key regulators of tissue development, homeostasis and repair, and abnormal FGF signalling is associated with various human diseases. In human and murine epidermis, FGF receptor 3 (FGFR3) activation causes benign skin tumours, but the consequences of FGFR3 deficiency in this tissue have not been determined. Here, we show that FGFR3 in keratinocytes is dispensable for mouse skin development, homeostasis and wound repair. However, the defect in the epidermal barrier and the resulting inflammatory skin disease that develops in mice lacking FGFR1 and FGFR2 in keratinocytes were further aggravated upon additional loss of FGFR3. This caused fibroblast activation and fibrosis in the FGFR1/FGFR2 double-knockout mice and even more in mice lacking all three FGFRs, revealing functional redundancy of FGFR3 with FGFR1 and FGFR2 for maintaining the epidermal barrier. Taken together, our study demonstrates that FGFR1, FGFR2 and FGFR3 act together to maintain epidermal integrity and cutaneous homeostasis, with FGFR2 being the dominant receptor.

Astro2020 APC White Paper. 2020 Vision: Towards a Sustainable OIR System

Abstract: optional): Open-access telescopes of all apertures are needed to operate a competitive and efficient national science program. While larger facilities contribute light-gathering power and angular resolution, smaller ones dominate for field of view, time-resolution, and especially, total available observing time, thereby enabling our entire, diversely-expert community. Smaller aperture telescopes therefore play a critical and indispensable role in advancing science. Thus, the divestment of NSF support for modest-aperture (1 – 4 m) public telescopes poses a serious threat to U.S. scientific leadership, which is compounded by the unknown consequences of the shift from observations driven by individual investigators to survey-driven science. Given the much higher cost efficiency and dramatic science returns for investments in modest aperture telescopes, it is hard to justify funding only the most expensive facilities. We therefore urge the Astro2020 panel to explicitly make the case for modest aperture facilities, and to recommend enhancing this funding stream to support and grow this critical component of the OIR System. Further study is urgently needed to prioritize the numerous exciting potential capabilities of smaller facilities,and to establish sustainable, long-term planning for the System. Cost category: Ground/Medium-Large over 10 years.