Nearby Continuum Research Articles

Metal line emission around $z<1$ galaxies

We characterize, for the first time, the average extended emission in multiple lines ( and around a statistical sample of 560 galaxies at $z By stacking the Multi Unit Spectroscopic Explorer (MUSE) 3D data from two large surveys, the MUSE Analysis of Gas around Galaxies (MAGG) and the MUSE Ultra Deep Field (MUDF), we detect significant emission out to approx 40 kpc, while and emission is detected out to approx 30 kpc. Via comparisons with the nearby average stellar continuum emission, we find that the line emission at 20--30 kpc likely arises from the disk-halo interface. Combining our results with that of our previous study at $z we find that the average surface brightness increases independently with redshift over $z and with stellar mass over which is likely driven by the star formation rate as well as the physical conditions of the gas. By comparing the observed line fluxes with photoionization models, we find that the ionization parameter declines with distance, going from log q (cm $) approx 7.7 at le 5 kpc to approx 7.3 at 20--30 kpc, which reflects a weaker radiation field in the outer regions of galaxies. The gas-phase metallicity shows no significant variation over 30 kpc, with a metallicity gradient of approx 0.003 dex kpc$^ $, which indicates an efficient mixing of metals on these scales. Alternatively, there could be a significant contribution from shocks and diffuse ionized gas to the line emission in the outer regions.

Time-dependent Stellar Flare Models of Deep Atmospheric Heating

Optical flares have been observed from magnetically active stars for many decades; unsurprisingly, the spectra and temporal evolution are complicated. For example, the shortcomings of optically thin, static slab models have long been recognized when confronted with the observations. A less incorrect—but equally simple—phenomenological T ≈ 9000 K blackbody model has instead been widely adopted in the absence of realistic (i.e., observationally tested) time-dependent, atmospheric models that are readily available. We use the RADYN code to calculate a grid of 1D radiative-hydrodynamic stellar flare models that are driven by short pulses of electron-beam heating. The flare heating rates in the low atmosphere vary over many orders of magnitude in the grid, and we show that the models with high-energy electron beams compare well to the global trends in flux ratios from impulsive-phase stellar flare, optical spectra. The models also match detailed spectral line-shape properties. We find that the pressure broadening and optical depths account for the broad components of the hydrogen Balmer γ lines in a powerful flare with echelle spectra. The self-consistent formation of the wings and nearby continuum level provides insight into how high-energy electron-beam heating evolves from the impulsive to the gradual decay phase in white-light stellar flares. The grid is publicly available, and we discuss possible applications.

Spectral and Imaging Observations of a C2.3 White-Light Flare from the Advanced Space-Based Solar Observatory (ASO-S) and the Chinese Hα\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$\\alpha $\\end{document}Solar Explorer (CHASE)

Solar white-light flares are characterized by an enhancement in the optical continuum, which are usually large flares (X- and M-class flares). Here, we report a small C2.3 white-light flare (SOL2022-12-20T04:10) observed by the Advanced Space-based Solar Observatory and the Chinese Hα\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$\\alpha $\\end{document}Solar Explorer (CHASE). This flare exhibits an increase of ≈ 6.4% in the photospheric Fe i line at 6569.2 Å and ≈ 3.2% in the nearby continuum. The continuum at 3600 Å also shows an enhancement of ≈ 4.7%. The white-light bright kernels are mainly located at the flare ribbons and co-spatial with nonthermal hard X-ray sources, which implies that the enhanced white-light emissions are related to nonthermal electron-beam heating. At the bright kernels, the Fe i line displays an absorption profile that has a good Gaussian shape, with a redshift up to ≈ 1.7 km s−1, while the Hα\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$\\alpha $\\end{document} line shows an emission profile having a central reversal. The Hα\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$\\alpha $\\end{document} line profile also shows a red or blue asymmetry caused by plasma flows with a velocity of several to tens of km s−1. It is interesting to find that the Hα\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$\\alpha $\\end{document} asymmetry is opposite at the conjugate footpoints. It is also found that the CHASE continuum increase seems to be related to the change in the photospheric magnetic field. Our study provides comprehensive characteristics of a small white-light flare that help understand the energy release process of white-light flares.

The White-light Emissions in Two X-class Flares Observed by ASO-S and CHASE

The white-light continuum emissions in solar flares (i.e., white-light flares) are usually observed on the solar disk but, in a few cases, off the limb. Here we present on-disk as well as off-limb continuum emissions at 3600 Å (in the Balmer continuum) in an X2.1 flare (SOL2023-03-03T17:52) and an X1.5 flare (SOL2023-08-07T20:46), respectively, observed by the White-light Solar Telescope on the Advanced Space-based Solar Observatory. These continuum emissions are seen at the ribbons for the X2.1 flare and on loops during the X1.5 event, in which the latter also appears in the decay phase. These emissions also show up in the pseudocontinuum images at Fe i λ6173 from the Helioseismic and Magnetic Imager on the Solar Dynamics Observatory. In addition, the ribbon sources in the X2.1 flare exhibit significant enhancements in the Fe i line at 6569.2 Å and the nearby continuum observed by the Chinese Hα Solar Explorer. It is found that the on-disk continuum emissions in the X2.1 flare are related to a nonthermal electron-beam heating either directly or indirectly, while the off-limb emissions in the X1.5 flare are associated with thermal plasma cooling or due to Thomson scattering. These comprehensive continuum observations provide good constraints on flare energy deposition models, which helps us to better understand the physical mechanism of white-light flares.

Spectral Observations and Modeling of a Solar White-light Flare Observed by CHASE

The heating mechanisms of solar white-light flares remain unclear. We present an X1.0 white-light flare on 2022 October 2 (SOL2022-10-02T20:25) observed by the Chinese Hα Solar Explorer that provides two-dimensional spectra in the visible light for the full solar disk with a seeing-free condition. The flare shows a prominent enhancement of ∼40% in the photospheric Fe i line at 6569.2 Å, and the nearby continuum also exhibits a maximum enhancement of ∼40%. For the continuum near the Fe i line at 6173 Å from the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory, it is enhanced up to ∼20%. At the white-light kernels, the Fe i line at 6569.2 Å has a symmetric Gaussian profile that is still in absorption and the Hα line at 6562.8 Å displays a very broad emission profile with a central reversal plus a red or blue asymmetry. The white-light kernels are cospatial with the microwave footpoint sources observed by the Expanded Owens Valley Solar Array and the time profile of the white-light emission matches that of the hard X-ray emission above 30 keV from the Gamma-ray Burst Monitor (GBM) on Fermi. These facts indicate that the white-light emission is qualitatively related to a nonthermal electron beam. We also perform a radiative hydrodynamic simulation with the electron-beam parameters constrained by the hard X-ray observations from Fermi/GBM. The result reveals that the white-light enhancement cannot be well explained by a pure electron-beam heating together with its induced radiative backwarming but may need additional heating sources such as Alfvén waves.

Analysis of the arm-like structure in the outer disk of PDS 70

Context. Observing dynamical interactions between planets and disks is key to understanding their formation and evolution. Two protoplanets have recently been discovered within the PDS 70 protoplanetary disk, along with an arm-like structure toward the northwest of the star. Aims. Our aim is to constrain the morphology and origin of this arm-like structure, and to assess whether it could trace a spiral density wave caused by the dynamical interaction between the planet PDS 70c and the disk. Methods. We analyzed polarized and angular differential imaging (PDI and ADI) data taken with VLT/SPHERE, spanning six years of observations. The PDI data sets were reduced using the irdap polarimetric data reduction pipeline, while the ADI data sets were processed using mustard, a novel algorithm based on an inverse problem approach to tackle the geometrical biases spoiling the images previously used for the analysis of this disk. Results. We confirm the presence of the arm-like structure in all PDI and ADI data sets, and extract its trace by identifying local radial maxima in azimuthal slices of the disk in each data set. We do not observe a southeast symmetric arm with respect to the disk minor axis, which seems to disfavor the previous hypothesis that the arm is the footprint of a double-ring structure. If the structure traces a spiral density wave following the motion of PDS 70c, we would expect 11°.28−0°.86+2°.20 rotation for the spiral in six years. However, we do not measure any significant movement of the structure. Conclusions. If the arm-like structure is a planet-driven spiral arm, the observed lack of rotation would suggest that the assumption of rigid-body rotation may be inappropriate for spirals induced by planets. We suggest that the arm-like structure may instead trace a vortex appearing as a one-armed spiral in scattered light due to projection effects. The vortex hypothesis accounts for both the lack of observed rotation and the presence of a nearby sub-millimeter continuum asymmetry detected with ALMA. Additional follow-up observations and dedicated hydrodynamical simulations could confirm this hypothesis.

Rapid turn-on of a luminous X-ray source in the candidate Lyman continuum emitting galaxy Tol 0440-381

ABSTRACT Chandra observations of the nearby candidate Lyman continuum (LyC) emitting galaxy Tol 0440-381 show brightening of an X-ray source by at least a factor of 4 to a luminosity of $1.6 \times 10^{40} \rm \, erg \, s^{-1}$ over 3.8 d. The X-ray emission likely arises from either a low-luminosity active galactic nucleus or an ultraluminous X-ray source. The properties of the X-ray source are similar to those found in Haro 11 and Tololo 1247-232, the only other LyC emitting galaxies that have been resolved in X-rays. All three galaxies host luminous, variable, and hard-spectrum X-ray sources that are likely accretion-powered. Accretion on to compact objects produces powerful outflows and ionizing radiation that could help enable LyC escape.

Remarks on the precise measurement of the X(3872) mass and its counting rate

The lineshapes of specific production experiments of the exotic state such as $X(3872)$ with $J^{PC}=1^{++}$ quantum numbers involving triangle singularities have been found to become highly sensitive to the binding energy of weakly bound states, thus offering in principle the opportunity of benchmark determinations. We critically analyze recent proposals to extract accurately and precisely the $X(3872)$ mass, which overlook an important physical effect by regarding their corresponding production lineshapes as a sharp mass distribution and, thus, neglecting the influence of initial nearby continuum states in the $1^{++}$ channel. The inclusion of these states implies an effective cancellation mechanism which operates at the current and finite experimental resolution of the detectors so that one cannot distinguish between the $1^{++}$ bound-state and nearby $D \bar D^*$ continuum states with the same quantum numbers. In particular, we show that the lineshape for resolutions above 1 MeV becomes rather insensitive to the binding energy unless high statistics is considered. The very existence of the observed bumps is a mere consequence of short distance correlated $\bar D D^*$ pairs, bound or unbound. The cancellation also provides a natural explanation for a recent study reporting missing but unknown decay channels in an absolute branching ratio global analysis of the $X(3872)$.

The Population of H ii Regions in NGC 7020

Abstract The galaxy NGC 7020 displays an exotic hexagonal ringlike central structure with conspicuous ansae located at two opposite vertices and a tenuous external ring populated by H ii regions. Inside and around the hexagonal structure, Hα emission is also present at the inner disk. To characterize the population of the H ii regions, as well as their ionizing clusters, we imaged NGC 7020 with narrowband Hα and nearby continuum filters attached to GMOS-S installed on the Gemini South telescope. We found 202 H ii regions or complexes of H ii regions evenly distributed between the outer ring and the central disk The nucleus and ansae also present Hα emission. The equivalent width of the Hα line (W Hα ) is systematically greater at the regions of the outer ring relative to those of the inner disk. We discuss the influence of the metallicity gradient of the disk and the upper limit of the masses of the initial mass function on W Hα , and we conclude that the data are still consistent with the occurrence of a younger burst of H ii region formation in the outer ring. The central regions present more massive clusters, M ≥ 106 M ⊙, than those of the outer ring (M ≤ 106 M ⊙). Three clusters within 5″ of the nucleus present masses higher than 108 M ⊙. The presence of diffuse Hα emission in the inner 5″ suggests gas flows in the nuclear region.

The Polarimetric and Helioseismic Imager on Solar Orbiter

Aims.This paper describes the Polarimetric and Helioseismic Imager on the Solar Orbiter mission (SO/PHI), the first magnetograph and helioseismology instrument to observe the Sun from outside the Sun-Earth line. It is the key instrument meant to address the top-level science question: How does the solar dynamo work and drive connections between the Sun and the heliosphere? SO/PHI will also play an important role in answering the other top-level science questions of Solar Orbiter, while hosting the potential of a rich return in further science.Methods.SO/PHI measures the Zeeman effect and the Doppler shift in the Fe I617.3 nm spectral line. To this end, the instrument carries out narrow-band imaging spectro-polarimetry using a tunable LiNbO3Fabry-Perot etalon, while the polarisation modulation is done with liquid crystal variable retarders. The line and the nearby continuum are sampled at six wavelength points and the data are recorded by a 2k × 2k CMOS detector. To save valuable telemetry, the raw data are reduced on board, including being inverted under the assumption of a Milne-Eddington atmosphere, although simpler reduction methods are also available on board. SO/PHI is composed of two telescopes; one, the Full Disc Telescope, covers the full solar disc at all phases of the orbit, while the other, the High Resolution Telescope, can resolve structures as small as 200 km on the Sun at closest perihelion. The high heat load generated through proximity to the Sun is greatly reduced by the multilayer-coated entrance windows to the two telescopes that allow less than 4% of the total sunlight to enter the instrument, most of it in a narrow wavelength band around the chosen spectral line.Results.SO/PHI was designed and built by a consortium having partners in Germany, Spain, and France. The flight model was delivered to Airbus Defence and Space, Stevenage, and successfully integrated into the Solar Orbiter spacecraft. A number of innovations were introduced compared with earlier space-based spectropolarimeters, thus allowing SO/PHI to fit into the tight mass, volume, power and telemetry budgets provided by the Solar Orbiter spacecraft and to meet the (e.g. thermal) challenges posed by the mission’s highly elliptical orbit.

A Novel Fog-IoT based Framework for Improving Performance of Cloud Computing

Internet-of-Things (IoT) has been considered as a fundamental part of our day by day existence with billions of IoT devices gathering information remotely and can interoperate within the current Internet framework. Fog computing is nothing but cloud computing to the extreme of network security. It provides computation and storage services via CSP (Cloud Service Provider) to end devices in the Internet of Things (IoT). Fog computing allows the data storing and processing any nearby network devices or nearby cloud endpoint continuum. Using fog computing, the designer can reduce the computation architecture of the IoT devices. Unfortunitily, this new paradigm IoT-Fog faces numerous new privacy and security issues, like authentication and authorization, secure communication, information confidentiality. Despite the fact that the customary cloud-based platform can even utilize heavyweight cryptosystem to upgrade security, it can't be performed on fog devices drectly due to reseource constraints. Additionally, a huge number of smart fog devices are fiercely disseminated and situated in various zones, which expands the danger of being undermined by some pernicious gatherings. Trait Based Encryption (ABE) is an open key encryption conspire that enables clients to scramble and unscramble messages dependent on client qualities, which ensures information classification and hearty information get to control. Be that as it may, its computational expense for encryption and unscrambling stage is straightforwardly corresponding to the multifaceted nature of the arrangements utilized. The points is to assess the planning, CPU burden, and memory burden, and system estimations all through each phase of the cloud-to-things continuum amid an analysis for deciding highlights from a finger tapping exercise for Parkinson's Disease patients. It will be appeared there are confinements to the proposed testbeds when endeavoring to deal with upwards of 35 customers at the same time. These discoveries lead us to a proper conveyance of handling the leaves the Intel NUC as the most suitable fog gadget. While the Intel Edison and Raspberry Pi locate a superior balance at in the edge layer, crossing over correspondence conventions and keeping up a self-mending network topology for "thing" devices in the individual territory organize.

Hα plumes or arms associated with the nucleus of NGC 7020

AbstractWe imaged the galaxy NGC 7020 with Gemini and GMOS-S interference filters centered on the Hα emission line and nearby continuum in order to detect and quantify the HII regions. Among about 200 HII regions, we detected two Hα emitting plumes or arms emerging from the galactic nucleus which, together with the nuclear emission, might indicate a process of feedback from the central region.

Angular Analysis of the e+e− → D(*)±D*∓ Process Near the Open Charm Threshold with Initial-State Radiation

The results of measurements of the exclusive cross section for the e+e− → D(*)±D*∓ process near the open charm threshold with initial-state radiation are presented. The analysis is based on the experimental data collected with the Belle detector at energies $$\sqrt s $$ equal to ϒ(4S), ϒ(5S) production energies, and energies of the nearby continuum corresponding to an integrated luminosity of 951 fb−1. The accuracy of the measurements of the cross sections is twice higher in comparison with the previous results of the Belle collaboration. An angular analysis is performed for the final state D*+D*− for the first time with the result that the cross section is decomposed into three components corresponding to the possible combinations of D*-meson polarizations in the final state.

A search for accreting young companions embedded in circumstellar disks

Context. In recent years, our understanding of giant planet formation progressed substantially. There have even been detections of a few young protoplanet candidates still embedded in the circumstellar disks of their host stars. The exact physics that describes the accretion of material from the circumstellar disk onto the suspected circumplanetary disk and eventually onto the young, forming planet is still an open question. Aims. We seek to detect and quantify observables related to accretion processes occurring locally in circumstellar disks, which could be attributed to young forming planets. We focus on objects known to host protoplanet candidates and/or disk structures thought to be the result of interactions with planets. Methods. We analyzed observations of six young stars (age 3.5–10 Myr) and their surrounding environments with the SPHERE/ZIMPOL instrument on the Very Large Telescope (VLT) in the Hα filter (656 nm) and a nearby continuum filter (644.9 nm). We applied several point spread function (PSF) subtraction techniques to reach the highest possible contrast near the primary star, specifically investigating regions where forming companions were claimed or have been suggested based on observed disk morphology. Results. We redetect the known accreting M-star companion HD142527 B with the highest published signal to noise to date in both Hα and the continuum. We derive new astrometry (r=62.8−2.7+2.1 mas and PA=(98.7±1.8)°) and photometry (ΔN_Ha = 6.3−0.3+0.2 mag, ΔB_Ha = 6.7 ± 0.2 mag and ΔCnt_Ha = 7.3−0.2+0.3 mag) for the companion in agreement with previous studies, and estimate its mass accretion rate (Ṁ ≈ 1−2 × 10−10 M⊙yr−1). A faint point-like source around HD135344 B (SAO206462) is also investigated, but a second deeper observation is required to reveal its nature. No other companions are detected. In the framework of our assumptions we estimate detection limits at the locations of companion candidates around HD100546, HD169142, and MWC 758 and calculate that processes involving Hα fluxes larger than ~ 8 × 10−14–10−15 erg s−1 cm−2 (Ṁ > 10−10−10−12 M⊙yr−1) can be excluded. Furthermore, flux upper limits of ~10−14−10−15 erg s−1 cm−2 (Ṁ < 10−11–10−12 M⊙yr−1) are estimated within the gaps identified in the disks surrounding HD135344 B and TW Hya. The derived luminosity limits exclude Hα signatures at levels similar to those previously detected for the accreting planet candidate LkCa15 b.

Magellan Adaptive Optics Imaging of PDS 70: Measuring the Mass Accretion Rate of a Young Giant Planet within a Gapped Disk

Abstract PDS 70b is a recently discovered and directly imaged exoplanet within the wide (≳40 au) cavity around PDS 70. Ongoing accretion onto the central star suggests that accretion onto PDS 70b may also be ongoing. We present the first high-contrast images at Hα (656 nm) and nearby continuum (643 nm) of PDS 70 utilizing the MagAO system. The combination of these filters allows for the accretion rate of the young planet to be inferred, as hot infalling hydrogen gas will emit strongly at Hα over the optical continuum. We detected a source in Hα at the position of PDS 70b on two sequential nights in 2018 May, for which we establish a false positive probability of <0.1%. We conclude that PDS 70b is a young, actively accreting planet. We utilize the Hα line luminosity to derive a mass accretion rate of M ˙ = 10 − 8 ± 1 M Jup yr−1, where the large uncertainty is primarily due to the unknown amount of optical extinction from the circumstellar and circumplanetary disks. PDS 70b represents the second case of an accreting planet interior to a disk gap, and is among the early examples of a planet observed during its formation.

A survey of TiOλ567 nm absorption in solar-type stars

Molecular absorption bands are estimators of stellar activity and spot cycles on magnetically active stars. We have previously introduced a new color index that compare absorption strength of the titanium oxide (TiO) at 567 nm with nearby continuum. In this paper we implement this index to measure long-term activity variations and the statistical properties of the index in a sample of 302 solar-type stars from the HARPS planet search program. The results indicate a pattern of change in star's activity, covers a range of periods from 2 years up to 17 years.

The measurement of flat fields and polarization offset from the routine observation data of a solar rotation

The correction of flat fields and polarization offset is a necessary step in the reduction of the full-disk solar observing data. The general used methods of the measurement of flat fields are summarized as follows. The first one is realized by randomly moving the solar telescope and making an average of thousands of observed images of the quiet region near the disk center, which is adopted by the large aperture solar telescopes with a small field-of-view. The second one is to shift the solar images with slightly different pointings, which is mostly used in the full-disk solar images. The third method is to use a diffuser to generate the uniform light source and it can be used in the full-disk solar images, too. Observing the nearby continuum of the selected working spectral line is generally used to obtain the polarization offset. It is worth to mention that, all these methods need special calibration observing mode and occupy the valuable scientific observation time. In the paper, we propose a new method to derive the flat fields and polarization offset from the routine observing data. Assuming that the flat fields and polarization offset do not change during a solar rotation, we firstly got the formula which can be used in the calculation of flat fields and polarization offset in the case of the ideal and real telescope guiding and pointing accuracy. The core algorithm in the formula is median process. Moreover, we obtained the flat fields and the crosstalk from Stokes I to Q , U and V using the above mentioned formula from series of the routine observed monochromatic image and Stokes Q / I , U / I and V / I images belonging to the Carrington Rotation 2144 observed by Huairou Solar Observing Station. The derived flat fields could not only reflect the small-scale dirty points but also the large-scale non-uniform pattern from the whole telescope system, which can be removed after the flat-fielding process. The distribution of the resulting Stokes V / I offset from Stokes I to V seems to be a Saddle surface, while that of the Stokes Q / I and U / I from I to Q , U is an upside-down bell shape. In order to evaluate the validity of the correction of the polarization offset we choose a quiet region near the solar limb as an example. The averaged value of Stokes V / I , Q / I and U / I in the region after polarization offset correction is −0.8×10−4, 0.9×10−4, 1.3×10−4, while that before correction is −6.8×10−4, 2×10−3, 1.7×10−3, respectively. It is quite clear that the Stokes V / I , Q / I and U / I improved a lot after the correction of the polarization offset. The main disadvantage of the method is that it can only correct the crosstalk from Stokes I to Q , U and V , incapable of the correction of that from Stokes V to Q and U . Some other methods are needed so as to make up the disadvantages. We suggest that the above mentioned method can be considered as one of the calibration methods for the space-borne or remote unattended full-disk solar observing instrument because it only uses the routine observation data without any other special calibration observation.

Comparison of the polarisation of line and continuum emission in a laser produced plasma

Anisotropic emission from a laser-produced aluminium plasma emission has been studied using time and polarisation resolved spectroscopy. The time-resolved degree of polarisation of emission from a bound – bound transition in Al+ (466.3 nm) was compared to the time-resolved degree of polarisation from nearby continuum emission. The results are interpreted in the framework of radiative recombination and statistical imbalances in the populations of magnetic sub-states. It is found that the continuum emission is more strongly polarised than the line emission. Thus, this technique is a valid alternative to gated LIBS.

Investigation of discrete states and quasidiscrete structures observed in Sm150 and Sm152 using the (p,tγ) reaction

New levels and $\ensuremath{\gamma}$-ray transitions were identified in $^{150,152}\mathrm{Sm}$ utilizing the $(p,t)$ reaction and particle-$\ensuremath{\gamma}$ coincidence data. A large, peak-like structure observed between 2.3--3.0 MeV in excitation energy in the triton energy spectra was also investigated. The orbital angular-momentum transfer was probed by comparing the experimental angular distributions of the outgoing tritons to calculated distorted wave Born approximation curves. The angular distributions of the outgoing tritons populating the peak-like structure are remarkably similar in the two reactions and are significantly different from the angular distributions associated with the nearby continuum region. Relative partial cross sections for the observed levels, angle averaged between 34 and 58 degrees, were measured. In $^{150}\mathrm{Sm}$, 39(4)% of the strength of the peak-like structure could be accounted for by the observed discrete states. This compares with a value of 93(15)% for $^{152}\mathrm{Sm}$.

New circumstellar structure in the T Tauri system

The immediate vicinity of T Tauri was observed with the new high-contrast imaging instrument SPHERE at the VLT to resolve remaining mysteries of the system, such as the putative small edge-on disk around T Tauri Sa, and the assignment of the complex outflow patterns to the individual stars. We used SPHERE IRDIS narrow-band classical imaging in Pa$\beta$, Br$\gamma$, and the $\nu$ = 1-0 S(1) line of H$_2$, as well as in the nearby continua to obtain high spatial resolution and high contrast images over the NIR spectral range. Line maps were created by subtracting the nearby continuum. We also re--analyzed coronagraphic data taken with SPHERE's integral field spectrograph in $J$- and $H$-band with the goal to obtain a precise extinction estimate to T Tauri Sb, and to verify the recently reported claim of another stellar or substellar object in the system. A previously unknown coiling structure is observed southwest of the stars in reflected light, which points to the vicinity of T Tauri N. We map the circumbinary emission from T Tauri S in $J$- and $H$-band scattered light for the first time, showing a morphology which differs significantly from that observed in $K$-band. H$_2$ emission is found southwest of the stars, near the coiling structure. We also detect the H$_2$ emitting region T Tauri NW. The motion of T Tauri NW with respect to T Tauri N and S between previous images and our 2014 data, provides strong evidence that the Southeast-Northwest outflow triggering T Tauri NW is likely to be associated with T Tauri S. We further present accurate relative photometry of the stars, confirming that T Tauri Sa is brightening again. Our analysis rules out the presence of the recently proposed companion to T Tauri N with high confidence.