The stellar population and complex structure of the bright-rimmed cloud IC 1396N

Context. IC 1396N is a bright-rimmed cloud associated with an intermediate-mass star-forming region, where a number of Herbig-Haro objects, H2 jet-like features, CO molecular outflows, and millimeter compact sources have been observed. Aims. To study in detail the complex structure of the IC 1396N core and the molecular outflows detected in the region and to reveal the presence of additional YSOs inside this globule. Methods. We carried out a deep survey of the IC 1396N region in the J, H, K' broadband filters and deep high-angular resolution observations in the H2 narrowband filter with NICS at the TNG telescope. The completeness limits in the 2MASS standard are Ks~17.5, H~18.5 and J~19.5. Results. A total of 736 sources have been detected in all three bands within the area where the JHK' images overlap. There are 128 sources detected only in HK', 67 detected only in K', and 79 detected only in H. We found only few objects exhibiting a Near-Infrared excess and no clear signs of clustering of sources towards the southern rim. In case of triggered star formation in the southern rim of the globule, this could be very recent, because it is not evidenced through Near-Infrared imaging alone. The H2 emission is complex and knotty and shows a large number of molecular hydrogen features spread over the region, testifying a recent star-formation activity throughout the whole globule. This emission is resolved into several chains or groups of knots that sometimes show a jet-like morphology. The shocked cloudlet model scenario previously proposed to explain the V-shaped morphology of the CO molecular outflow powered by the intermediate-mass YSO BIMA 2 seems to be confirmed by the presence of H2 emission at the position of the deflecting western clump. New possible flows have been discovered in the globule,Comment: Comments: 19 pages, 5 tables, 7 figures. Accepted for publication in A&

Anisotropic magnetic properties of CeAg2_2Ge2_2 single crystal

In order to investigate the anisotropic magnetic properties of CeAg$_2$Ge$_2$, we have successfully grown the single crystals, for the first time, by high temperature solution growth (flux) method. We have performed a detailed study of the grown single crystals by measuring their electrical resistivity, magnetic susceptibility, magnetization, specific heat and magnetoresistance. A clear anisotropy and an antiferromagnetic transition at $T_{\rm N}$ = 4.6 K have been observed in the magnetic properties. The magnetic entropy reaches $R$ ln 4 at 20 K indicating that the ground state and the first excited state are very closely spaced (a quasi-quartet state). From the specific heat measurements and crystalline electric field (CEF) analysis of the magnetic susceptibility, we have found the level splitting energies as 5 K and 130 K. The magnetization measurements reveal that the a-axis is the easy axis of magnetization and the saturation moment is $\mu_{\rm s}$ = 1.6 $\mu_{\rm B}$/Ce, corroborating the previous neutron diffraction measurements on a polycrystalline sample.Comment: Submitted to Phys. Rev.

Who Is Eating the Outflow?: High-Angular Resolution Study of an Intermediate-Mass Protostar in L1206

Up to now only a few intermediate-mass molecular outflows have been studied with enough high-angular resolution. The aim of this work is to study in detail the intermediate-mass YSO IRAS 22272+6358A, which is embedded in L1206, and its molecular outflow, in order to investigate the interaction of the outflow with the dense protostellar material, and to compare their properties with those of lower mas counterparts. We carried out OVRO observations of the 2.7 mm continuum emission, CO(1-0), C18O(1-0), and HC3N(12-11) in order to map with high-angular resolution the core of L1206, and to derive the properties of the dust emission, the molecular outflow and the dense protostellar envelope. The 2.7 mm continuum emission has been resolved into four sources, labeled OVRO~1, 2, 3, and 4. The intermediate-mass Class~0/I object OVRO 2, with a mass traced by the dust emission of 14.2 Msun, is the source associated with IRAS 22272+6358A. The CO(1-0) observations have revealed a very collimated outflow driven by OVRO 2, at a PA ~140 degr, that has a very weak southeastern red lobe and a much stronger northwestern blue lobe. Photodissociation toward the red lobe produced by the ionization front coming from the bright-rimmed diffuse HII region could be responsible of the morphology of the outflow. The spatial correlation between the outflow and the elongated dense protostellar material traced by HC3N(12-11) suggests an interaction between the molecular outflow and the protostellar envelope. Shocks produced by the molecular outflow, and possibly by the shock front preceding the ionization front could account for the southern enhancement of HC3N. The properties of the intermediate-mass protostar OVRO 2 and the molecular outflow are consistent with those of lower mass counterparts.Comment: 14 pages, 12 figures, 5 tables. Accepted for publication by A&

The Distance to the Galactic Center Derived From Infrared Photometry of Bulge Red Clump Stars

On the basis of the near infrared observations of bulge red clump stars near the Galactic center, we have determined the galactocentric distance to be R_0 = 7.52 +- 0.10 (stat) +- 0.35 (sys) kpc. We observed the red clump stars at |l| < 1.0 deg and 0.7 deg < |b| < 1.0 deg with the IRSF 1.4 m telescope and the SIRIUS camera in the H and Ks bands. After extinction and population corrections, we obtained (m - M)_0 = 14.38 +- 0.03 (stat) +- 0.10 (sys). The statistical error is dominated by the uncertainty of the intrinsic local red clump stars' luminosity. The systematic error is estimated to be +- 0.10 including uncertainties in extinction and population correction, zero-point of photometry, and the fitting of the luminosity function of the red clump stars. Our result, R_0 = 7.52 kpc, is in excellent agreement with the distance determined geometrically with the star orbiting the massive black hole in the Galactic center. The recent result based on the spatial distribution of globular clusters is also consistent with our result. In addition, our study exhibits that the distance determination to the Galactic center with the red clump stars, even if the error of the population correction is taken into account, can achieve an uncertainty of about 5%, which is almost the same level as that in recent geometrical determinations.Comment: 14 pages, 4 figures, accepted by Ap

An orally available cancer drug AZD6738 prevents type 1 diabetes

Type 1 diabetes (T1D) affects three million Americans, with 80 new people diagnosed each day. T1D is currently uncurable and there is an urgent need to develop additional drug candidates to achieve the prevention of T1D. We propose AZD6738 (ATRi), an orally available drug currently in phases I and II of clinical trials for various cancers, as a novel candidate to prevent T1D. Based on previously reported findings of ATRi inducing cell death in rapidly proliferating T cells, we hypothesized that this drug would specifically affect self-antigen activated diabetogenic T cells. These cells, if left unchecked, could otherwise lead to the destruction of pancreatic β cells, contributing to the development of T1D. This work demonstrates that increasing the duration of ATRi treatment provides extended protection against T1D onset. Remarkably, 5-week ATRi treatment prevented T1D in a robust adoptive transfer mouse model. Furthermore, the splenocytes of animals that received 5-week ATRi treatment did not transfer immune-mediated diabetes, while the splenocytes from control animal transferred the disease in 10 days. This work shows that ATRi prevents T1D by specifically inducing cell death in self-antigen activated, highly proliferative diabetogenic T cells through the induction of DNA damage, resulting in the inhibition of IFNγ production and proliferation. These findings support the consideration of repurposing ATRi for T1D prevention

HH135/HH136 - a luminous H2_2 outflow towards a high-mass protostar

Near-infrared observations towards the luminous IRAS source IRAS11101-5928 and the associated Herbig-Haro objects HH135/HH136 are presented. The observations reveal the presence of a well-collimated, parsec-sized H$_2$ outflow with a total H$_2$ luminosity of about $2L_\odot$. The bulk of the molecular gas is characterized by a ro-vibrational excitation temperature of $2000\pm200$ K. A small fraction (0.3%) of the molecular gas is very hot, with excitation temperatures around 5500 K. The molecular emission is associated with strong [FeII] emission. The H$_2$ and [FeII] emission characteristics indicate the presence of fast, dissociative J-shocks at speeds of $v_\mathrm{s} \approx$ 100 km s$^{-1}$. Electron densities of $n_\mathrm{e}$ = 3500-4000 cm$^{-3}$ are inferred from the [FeII] line ratios. The large H$_2$ luminosity combined with the very large source luminosity suggests that the high-mass protostar that powers the HH135/HH136 flow forms via accretion, but with a significantly increased accretion rate compared to that of low-mass protostars

The IC1396N proto-cluster at a scale of 250 AU

We investigate the mm-morphology of IC1396N with unprecedented spatial resolution to analyze its dust and molecular gas properties, and draw comparisons with objects of similar mass. We have carried out sensitive observations in the most extended configurations of the IRAM Plateau de Bure interferometer, to map the thermal dust emission at 3.3 and 1.3mm, and the emission from the $J$=13$_k\to12_k$ hyperfine transitions of methyl cyanide (CH$_3$CN). We unveil the existence of a sub-cluster of hot cores in IC1396N, distributed in a direction perpendicular to the emanating outflow. The cores are embedded in a common envelope of extended and diffuse dust emission. We find striking differences in the dust properties of the cores ($\beta\simeq$ 0) and the surrounding envelope ($\beta\simeq$ 1), very likely testifying to differences in the formation and processing of dust material. The CH$_3$CN emission peaks towards the most massive hot core and is marginally extended in the outflow direction

Diversification in the Archean Biosphere: Insight from NanoSIMS of Microstructures in the Farrel Quartzite of Australia

The nature of early life on Earth is difficult to assess because potential Early Archean biosignatures are commonly poorly preserved. Interpretations of such materials have been contested, and abiotic or epigenetic derivations have been proposed (summarized in [1]). Yet, an understanding of Archean life is of astrobiological importance, as knowledge of early evolutionary processes on Earth could provide insight to development of life on other planets. A recently-discovered assemblage of organic microstructures in approx.3 Ga charts of the Farrel Quartzite (FQ) of Australia [2-4] includes unusual spindle-like forms and a variety of spheroids. If biogenicity and syngeneity of these forms could be substantiated, the FQ assemblage would provide a new view of Archean life. Our work uses NanoSIMS to further assess the biogenicity and syngeneity of FQ microstructures. In prior NanoSIMS studies [5-6], we gained an understanding of nano-scale elemental distributions in undisputed microfossils from the Neoproterozoic Bitter Springs Formation of Australia. Those results provide a new tool with which to evaluate poorly preserved materials that we might find in Archean sediments and possibly in extraterrestrial materials. We have applied this tool to the FQ forms