Deconvolution with correct sampling

A new method for improving the resolution of astronomical images is presented. It is based on the principle that sampled data cannot be fully deconvolved without violating the sampling theorem. Thus, the sampled image should not be deconvolved by the total Point Spread Function, but by a narrower function chosen so that the resolution of the deconvolved image is compatible with the adopted sampling. Our deconvolution method gives results which are, in at least some cases, superior to those of other commonly used techniques: in particular, it does not produce ringing around point sources superimposed on a smooth background. Moreover, it allows to perform accurate astrometry and photometry of crowded fields. These improvements are a consequence of both the correct treatment of sampling and the recognition that the most probable astronomical image is not a flat one. The method is also well adapted to the optimal combination of different images of the same object, as can be obtained, e.g., from infrared observations or via adaptive optics techniques.Comment: 22 pages, LaTex file + 10 color jpg and postscript figures. To be published in ApJ, Vol 484 (1997 Feb.

High accuracy transit photometry of the planet OGLE-TR-113b with a new deconvolution-based method

A high accuracy photometry algorithm is needed to take full advantage of the potential of the transit method for the characterization of exoplanets, especially in deep crowded fields. It has to reduce to the lowest possible level the negative influence of systematic effects on the photometric accuracy. It should also be able to cope with a high level of crowding and with large scale variations of the spatial resolution from one image to another. A recent deconvolution-based photometry algorithm fulfills all these requirements, and it also increases the resolution of astronomical images, which is an important advantage for the detection of blends and the discrimination of false positives in transit photometry. We made some changes to this algorithm in order to optimize it for transit photometry and used it to reduce NTT/SUSI2 observations of two transits of OGLE-TR-113b. This reduction has led to two very high precision transit light curves with a low level of systematic residuals, used together with former photometric and spectroscopic measurements to derive new stellar and planetary parameters in excellent agreement with previous ones, but significantly more precise.Comment: 8 pages, 4 figure

Fancine 2003, n. 08

Abstract not availabl

SPECULOOS: a network of robotic telescopes to hunt for terrestrial planets around the nearest ultracool dwarfs

We present here SPECULOOS, a new exoplanet transit search based on a network of 1m-class robotic telescopes targeting the $\sim$1200 ultracool (spectral type M7 and later) dwarfs bright enough in the infrared ($K$-mag $\leq 12.5$) to possibly enable the atmospheric characterization of temperate terrestrial planets with next-generation facilities like the $\textit{James Webb Space Telescope}$. The ultimate goals of the project are to reveal the frequency of temperate terrestrial planets around the lowest-mass stars and brown dwarfs, to probe the diversity of their bulk compositions, atmospheres and surface conditions, and to assess their potential habitability.Comment: 21 pages, 13 figures, 1 table. Proceedings of SPI

CCR2 Acts as Scavenger for CCL2 during Monocyte Chemotaxis

<div><h3>Background</h3><p>Leukocyte migration is essential for effective host defense against invading pathogens and during immune homeostasis. A hallmark of the regulation of this process is the presentation of chemokines in gradients stimulating leukocyte chemotaxis via cognate chemokine receptors. For efficient migration, receptor responsiveness must be maintained whilst the cells crawl on cell surfaces or on matrices along the attracting gradient towards increasing concentrations of agonist. On the other hand agonist-induced desensitization and internalization is a general paradigm for chemokine receptors which is inconsistent with the prolonged migratory capacity.</p> <h3>Methodology/Principal Findings</h3><p>Chemotaxis of monocytes was monitored in response to fluorescent CCL2-mCherry by time-lapse video microscopy. Uptake of the fluorescent agonist was used as indirect measure to follow the endogenous receptor CCR2 expressed on primary human monocytes. During chemotaxis CCL2-mCherry becomes endocytosed as cargo of CCR2, however, the internalization of CCR2 is not accompanied by reduced responsiveness of the cells due to desensitization.</p> <h3>Conclusions/Significance</h3><p>During chemotaxis CCR2 expressed on monocytes internalizes with the bound chemoattractant, but cycles rapidly back to the plasma membrane to maintain high responsiveness. Moreover, following relocation of the source of attractant, monocytes can rapidly reverse their polarization axis organizing a new leading edge along the newly formed gradient, suggesting a uniform distribution of highly receptive CCR2 on the plasma membrane. The present observations further indicate that during chemotaxis CCR2 acts as scavenger consuming the chemokine forming the attracting cue.</p> </div

Circadian-Related Heteromerization of Adrenergic and Dopamine D4 Receptors Modulates Melatonin Synthesis and Release in the Pineal Gland

Dopamine and adrenergic receptor complexes form under a circadian-regulated cycle and directly modulate melatonin synthesis and release from the pineal gland

Circadian-Related Heteromerization of Adrenergic and Dopamine D4 Receptors Modulates Melatonin Synthesis and Release in the Pineal Gland

Dopamine and adrenergic receptor complexes form under a circadian-regulated cycle and directly modulate melatonin synthesis and release from the pineal gland

TOI-2084 b and TOI-4184 b: two new sub-Neptunes around M dwarf stars

We present the discovery and validation of two TESS exoplanets orbiting nearby M dwarfs: TOI-2084b, and TOI-4184b. We characterized the host stars by combining spectra from Shane/Kast and Magellan/FIRE, SED (Spectral Energy Distribution) analysis, and stellar evolutionary models. In addition, we used Gemini-South/Zorro & -North/Alopeke high-resolution imaging, archival science images, and statistical validation packages to support the planetary interpretation. We performed a global analysis of multi-colour photometric data from TESS and ground-based facilities in order to derive the stellar and planetary physical parameters for each system. We find that TOI-2084b and TOI-4184b are sub-Neptune-sized planets with radii of Rp = 2.47 +/- 0.13R_Earth and Rp = 2.43 +/- 0.21R_Earth, respectively. TOI-2084b completes an orbit around its host star every 6.08 days, has an equilibrium temperature of T_eq = 527 +/- 8K and an irradiation of S_p = 12.8 +/- 0.8 S_Earth. Its host star is a dwarf of spectral M2.0 +/- 0.5 at a distance of 114pc with an effective temperature of T_eff = 3550 +/- 50 K, and has a wide, co-moving M8 companion at a projected separation of 1400 au. TOI-4184b orbits around an M5.0 +/- 0.5 type dwarf star (Kmag = 11.87) each 4.9 days, and has an equilibrium temperature of T_eq = 412 +/- 8 K and an irradiation of S_p = 4.8 +/- 0.4 S_Earth. TOI-4184 is a metal poor star ([Fe/H] = -0.27 +/- 0.09 dex) at a distance of 69 pc with an effective temperature of T_eff = 3225 +/- 75 K. Both planets are located at the edge of the sub-Jovian desert in the radius-period plane. The combination of the small size and the large infrared brightness of their host stars make these new planets promising targets for future atmospheric exploration with JWST.Comment: Accepted for publication in A&

TOI-2084 b and TOI-4184 b:two new sub-Neptunes around M dwarf stars

Funding: The research leading to these results has received funding from the ARC grant for Concerted Research Actions, financed by the Wallonia-Brussels Federation. This research is in part funded by the European Union’s Horizon 2020 research and innovation program (grants agreements n◦ 803193/BEBOP), and from the Science and Technology Facilities Council (STFC; grant n◦ ST/S00193X/1). U.G.J. gratefully acknowledges support from tthe European Union H2020-MSCA-ITN-2019 under grant No. 860470 (CHAMELEON). We acknowledge funding from the European Research Council under the ERC Grant Agreement n. 337591-ExTrA.We present the discovery and validation of two TESS exoplanets orbiting nearby M dwarfs: TOI-2084 b, and TOI-4184b. We characterized the host stars by combining spectra from Shane/Kast and Magellan/FIRE, spectral energy distribution analysis, and stellar evolutionary models. In addition, we used Gemini-South/Zorro & -North/Alopeke high-resolution imaging, archival science images, and statistical validation packages to support the planetary interpretation. We performed a global analysis of multi-colour photometric data from TESS and ground-based facilities in order to derive the stellar and planetary physical parameters for each system. We find that TOI-2084 band TOI-4184 bare sub-Neptune-sized planets with radii of Rp = 2.47 ± 0.13R⊕ and Rp = 2.43 ± 0.21 R⊕, respectively. TOI-2084 b completes an orbit around its host star every 6.08 days, has an equilibrium temperature of Teq = 527 ± 8 K and an irradiation of Sp = 12.8 ± 0.8 S⊕. Its host star is a dwarf of spectral M2.0 ± 0.5 at a distance of 114 pc with an effective temperature of Teff = 3550 ± 50 K, and has a wide, co-moving M8 companion at a projected separation of 1400 au. TOI-4184 b orbits around an M5.0 ± 0.5 type dwarf star (Kmag = 11.87) each 4.9 days, and has an equilibrium temperature of Teq = 412 ± 8 K and an irradiation of Sp = 4.8 ± 0.4 S⊕. TOI-4184 is a metal poor star ([Fe/H] = −0.27 ± 0.09 dex) at a distance of 69 pc with an effective temperature of Teff = 3225 ± 75 K. Both planets are located at the edge of the sub-Jovian desert in the radius-period plane. The combination of the small size and the large infrared brightness of their host stars make these new planets promising targets for future atmospheric exploration with JWST.Publisher PDFPeer reviewe