Enough Is as Good as a Feast

Ipse Dixit, the podcast on legal scholarship, provides a valuable service to the legal community and particularly to the legal academy. The podcast’s hosts skillfully interview guests about their legal and law-related scholarship, helping those guests communicate their ideas clearly and concisely. In this review essay, I argue that Ipse Dixit has made a major contribution to legal scholarship by demonstrating in its interview episodes that law review articles are neither the only nor the best way of communicating scholarly ideas. This contribution should be considered “scholarship,” because one of the primary goals of scholarship is to communicate new ideas

Replacing Tinker

In this Article, I wish to question whether reaffirming the animating spirit of Tinker is the best way to protect student speech rights. In allowing schools to punish student speech that school officials reasonably believe could be substantially disruptive, Tinker founds students’ free expression rights on unstable ground. This is true for two reasons. First, the Tinker standard allows school officials to regulate student speech based on their own perceptions of what its impacts will be. While these perceptions must be reasonable, courts have shown extraordinary deference to educators’ claims that student speech could be substantially disruptive. Second, the substantial disruption standard allows speech to be restricted not because it is in some way unlawful, but rather because of what others’ reactions might be to it. As I discuss below, government regulations with either one of these defects would generally be found unconstitutional in a nonschool context, because they give government officials too much discretion to burden or proscribe unpopular speech—the very harm the First Amendment’s free speech guarantee is designed to guard against. For these reasons, I argue that Tinker’s substantial disruption standard ought to be replaced by something like the public forum doctrine, which tailors governments’ power to restrict speech in a given forum based on the forum’s traditional use and the government’s role in creating it and is highly skeptical of government discretion in determining what expression will be allowed in the forum. In my view, schools should be allowed to regulate student speech only when they create or control the forum in which it is expressed. Otherwise, they should be without the power to regulate student speech. Even within the forums that they control, I argue that schools’ ability to regulate student speech should be circumscribed

A library of near-infrared integral field spectra of young M-L dwarfs

We present a library of near-infrared (1.1-2.45 microns) medium-resolution (R~1500-2000) integral field spectra of 15 young M6-L0 dwarfs, composed of companions with known ages and of isolated objects. We use it to (re)derive the NIR spectral types, luminosities and physical parameters of the targets, and to test (BT-SETTL, DRIFT-PHOENIX) atmospheric models. We derive infrared spectral types L0+-1, L0+-1, M9.5+-0.5, M9.5+-0.5, M9.25+-0.25, M8+0.5-0.75, and M8.5+-0.5 for AB Pic b, Cha J110913-773444, USco CTIO 108B, GSC 08047-00232 B, DH Tau B, CT Cha b, and HR7329B, respectively. BT-SETTL and DRIFT-PHOENIX models yield close Teff and log g estimates for each sources. The models seem to evidence a 600-300+600 K drop of the effective temperature at the M-L transition. Assuming the former temperatures are correct, we derive new mass estimates which confirm that DH Tau B, USco CTIO 108B, AB Pic b, KPNO Tau 4, OTS 44, and Cha1109 lay inside or at the boundary of the planetary mass range. We combine the empirical luminosities of the M9.5-L0 sources to the Teff to derive semi-empirical radii estimates that do not match "hot-start" evolutionary models predictions at 1-3 Myr. We use complementary data to demonstrate that atmospheric models are able to reproduce the combined optical and infrared spectral energy distribution, together with the near-infrared spectra of these sources simultaneously. But the models still fail to represent the dominant features in the optical. This issue casts doubts on the ability of these models to predict correct effective temperatures from near-infrared spectra alone. We advocate the use of photometric and spectroscopic data covering a broad range of wavelengths to study the properties of very low mass young companions to be detected with the planet imagers (Subaru/SCExAO, LBT/LMIRCam, Gemini/GPI, VLT/SPHERE).Comment: 27 pages, 14 tables, 19 figures, accepted for publication in Astronomy & Astrophysic

Near-infrared integral-field spectra of the planet/brown dwarf companion AB Pic b

Chauvin et al. 2005 imaged a co-moving companion at ~260 AU from the young star AB Pic A. Evolutionary models predictions based on J H K photometry of AB Pic b suggested a mass of ~13 - 14 MJup, placing the object at the deuterium-burning boundary. We used the adaptive-optics-fed integral field spectrograph SINFONI to obtain high quality medium-resolution spectra of AB Pic b (R = 1500-2000) over the 1.1 - 2.5 microns range. Our analysis relies on the comparison of our spectra to young standard templates and to the latest libraries of synthetic spectra developed by the Lyon's Group. AB Pic b is confirmed to be a young early-L dwarf companion. We derive a spectral type L0-L1 and find several features indicative of intermediate gravity atmosphere. A comparison to synthetic spectra yields Teff = 2000+100-300 K and log(g) = 4 +- 0.5 dex. The determination of the derived atmospheric parameters of AB Pic b is limited by a non-perfect match of current atmosphere spectra with our near-infrared observations of AB Pic b. The current treatment of dust settling and missing molecular opacity lines in the atmosphere models could be responsible. By combining the observed photometry, the surface fluxes from atmosphere models and the known distance of the system, we derive new mass, luminosity and radius estimates of AB Pic b. They confirm independently the evolutionary model predictions. We finally review the current methods used to characterize planetary mass companions and discuss them in the perspective of future planet deep imaging surveys.Comment: 8 pages, 8 figure