A5086910300- Astrophysics and Star Formation Studies
- Stellar, planetary, and galactic studies
- Molecular Spectroscopy and Structure
- Astronomy and Astrophysical Research
- Galaxies: Formation, Evolution, Phenomena
- Atmospheric Ozone and Climate
- Astronomical Observations and Instrumentation
- Astro and Planetary Science
- Spectroscopy and Laser Applications
- Advanced Chemical Physics Studies
- Calibration and Measurement Techniques
- Advanced Combustion Engine Technologies
- Phase Equilibria and Thermodynamics
- Gas Dynamics and Kinetic Theory
- Infrared Target Detection Methodologies
- Quantum, superfluid, helium dynamics
- Atomic and Molecular Physics
- Optical Polarization and Ellipsometry
- Methane Hydrates and Related Phenomena
- Adaptive optics and wavefront sensing
- Advanced Thermodynamics and Statistical Mechanics
- Superconducting and THz Device Technology
- Carbon Dioxide Capture Technologies
- Atomic and Subatomic Physics Research
- Scientific Research and Discoveries
Cardiff University
2017-2025
University of Leeds
2015-2018
Max Planck Institute for Astronomy
2010-2018
Max Planck Society
2011-2015
University of Michigan
2006-2012
Private University College of Education of the Diocese of Linz
2010
PC Krause & Associates (United States)
2010
We present Submillimeter Array (SMA) λ = 0.88 and 1.3 mm broad-band observations, Very Large (VLA) observations in NH3 (J, K) (1,1) up to (5,5), H2O CH3OH maser lines towards the two most massive molecular clumps infrared dark cloud (IRDC) G11.11−0.12. Sensitive high-resolution images reveal hierarchical fragmentation dense gas from ∼1 pc clump scale down ∼0.01 condensation scale. At each scale, mass of fragments is orders magnitude larger than Jeans mass. This common all four IRDC we...
Hi-GAL is a large-scale survey of the Galactic plane, performed with Herschel in five infrared continuum bands between 70 and 500 $\mu$m. We present band-merged catalogue spatially matched sources their properties derived from fits to spectral energy distributions (SEDs) heliocentric distances, based on photometric catalogs presented Molinari et al. (2016a), covering portion plane $-71.0^{\circ}< \ell < 67.0^{\circ}$. The contains 100922 regular SED, 24584 which show $\mu$m counterpart are...
Context: The past decade has witnessed a large number of Galactic plane surveys at angular resolutions below 20". However, no comparable high-resolution survey exists long radio wavelengths around 21cm in line and continuum emission. Methods: Employing the Very Large Array (VLA) C-array configuration program, we observe HI line, four OH lines, nineteen Halpha recombination lines as well emission from 1 to 2GHz full polarization over part first quadrant. Results: Covering longitudes 14.5...
Context. The temperature and density structure of molecular cloud cores are the most important physical quantities that determine course protostellar collapse properties stars they form. Nevertheless, profiles often rely either on simplifying assumption isothermality or observationally poorly constrained model profiles. instruments Herschel satellite provide us for first time with both spectral coverage spatial resolution is needed to directly measure dust nearby cores.
We describe new Hi-GAL based maps of the entire Galactic Plane, obtained using continuum data in wavelength range 70–500 μm. These are derived with PPMAP procedure, and therefore represent a significant improvement over those standard analysis techniques. Specifically they have greatly improved resolution (12 arcsec) and, addition to more accurate integrated column densities mean dust temperatures, give temperature-differential densities, i.e., separate density twelve distinct temperature...
Context. High-mass stars form in clusters, but neither the early fragmentation processes nor detailed physical leading to most massive are well understood. Aims. We aim understand fragmentation, as disk formation, outflow generation, and chemical during high-mass star formation on spatial scales of individual cores. Methods. Using IRAM Northern Extended Millimeter Array (NOEMA) combination with 30 m telescope, we have observed large program CORE 1.37 mm continuum spectral line emission at...
In this paper we provide a comprehensive description of the internal dynamics G0.253+0.016 (a.k.a. 'the Brick'); one most massive and dense molecular clouds in Galaxy to lack signatures widespread star formation. As potential host future generation high-mass stars, understanding largely quiescent like is critical importance. paper, reanalyse Atacama Large Millimeter Array cycle 0 HNCO $J=4(0,4)-3(0,3)$ data at 3 mm, using two new pieces software which make available community. First,...
Our understanding of how molecular clouds form in the interstellar medium (ISM) would be greatly helped if we had a reliable observational tracer gas flows responsible for forming clouds. Fine structure emission from singly ionised and neutral carbon ([CII], [CI]) rotational line CO are all observed to associated with However, it remains unclear whether any these tracers can used study inflow onto an assembling cloud, or they primarily trace cloud once has already assembled. In this paper,...
ABSTRACT The SEDIGISM (Structure, Excitation and Dynamics of the Inner Galactic Interstellar Medium) survey used APEX telescope to map 84 deg2 plane between ℓ = −60° +31° in several molecular transitions, including 13CO (2 – 1) C18O 1), thus probing moderately dense (∼103 cm−3) component interstellar medium. With an angular resolution 30 arcsec a typical 1σ sensitivity 0.8–1.0 K at 0.25 km s−1 velocity resolution, it gives access wide range structures, from individual star-forming clumps...
We present the $360^\circ$ catalogue of physical properties Hi-GAL compact sources, detected between 70 and 500 $\mu$m. This release not only completes analogous previously produced by collaboration for $-71^\circ \lesssim \ell 67^\circ$, but also meaningfully improves it thanks to a new set heliocentric distances, 120808 in total. About third 150223 entries are located newly added portion Galactic plane. A first classification based on detection at $\mu$m as signature ongoing star-forming...
ABSTRACT High-mass stars have an enormous influence on the evolution of interstellar medium in galaxies, so it is important that we understand how they form. We examine central clumps within a sample seven infrared-dark clouds (IRDCs) with range masses and morphologies. use 1-pc-scale observations from Northern Extended Millimeter Array (NOEMA) IRAM 30m telescope to trace dense cores 2.8-mm continuum, gas kinematics C18O, HCO+, HNC, N2H+ (J = 1–0). supplement our continuum six IRDCs observed...
Context. Stars are born deeply embedded in molecular clouds. In the earliest phases, protostars emit bulk of their radiation far-infrared wavelength range, where Herschel is perfectly suited to probe at high angular resolution and dynamic range. high-mass regime, birthplaces thought be high-density structures known as infrared-dark clouds (IRDCs). While massive IRDCs believed have right conditions give rise stars clusters, evolutionary sequence this process not well-characterized.
<i>Context. <i/>Infrared-dark clouds (IRDCs) are the precursors to massive stars and stellar clusters. G011.11–0.12 is a well-studied filamentary IRDC, though, date, absence of far-infrared data with sufficient spatial resolution has limited understanding structure star-formation activity.<i>Aims. <i/>We use <i>Herschel<i/> study embedded population young pre- protostellar cores in this IRDC. <i>Methods. examine cloud structure, which appears absorption at short wavelength emission longer...
Throughout the Milky Way, molecular clouds typically appear filamentary, and mounting evidence indicates that this morphology plays an important role in star formation. What is not known to what extent dense filaments most closely associated with formation are connected surrounding diffuse up arbitrarily large scales. How these cradles of linked Way's spiral structure? Using archival Galactic plane survey data, we have used multiple datasets search large-scale, velocity-coherent plane. In...
(Abriged) In the framework of Herschel GTKP "The earliest phases star formation", we have imaged B68 between 100 and 500 um. Ancillary (sub)mm data, spectral line maps 12/13CO(2-1) transitions as well a NIR extinction map were added to analysis. We employed ray-tracing algorithm derive 2D mid-plane dust temperature volume density distribution without suffering from LoS averaging effects simple SED fitting procedures. Additional 3D radiative transfer calculations investigate connection...
Aims: We resolve the length-scales for filament formation and fragmentation (res. <=0.1pc), in particular Jeans length cylinder scale. Methods: observed prototypical high-mass star-forming IRDC18223 with Plateau de Bure Interferometer (PdBI) 3.2mm continuum N2H+(1-0) line emission a ten field mosaic at spatial resolution of ~4'' (~14000AU). Results: The dust resolves into chain least 12 relatively regularly spaced cores. mean separation between cores is ~0.40(+-0.18)pc. While this...
ATLASGAL is a 870-mircon dust survey of 420 square degrees the inner Galactic plane and has been used to identify ~10 000 dense molecular clumps. Dedicated follow-up observations complementary surveys are characterise physical properties these clumps, map their distribution investigate evolutionary sequence for high-mass star formation. The analysis data ongoing: we present an up-to-date version catalogue. We have classified 5007 clumps into four stages (quiescent, protostellar, young...
Star formation in molecular clouds is intimately linked to their internal mass distribution. We present an unprecedentedly detailed analysis of the column density structure a high-mass, filamentary cloud, namely IRDC G11.11-0.12 (G11). use two novel mapping techniques: high-resolution (FWHM=2", or ~0.035 pc) dust extinction near- and mid-infrared, emission with Herschel satellite. These completely independent techniques yield strikingly good agreement, highlighting complementarity...
We present a series of smoothed particle hydrodynamical models G0.253+0.016 (also known as 'The Brick'), very dense molecular cloud that lies close to the Galactic Centre. explore how its gas and dust temperatures react we vary strength both interstellar radiation field (ISRF) cosmic ray ionisation rate (CRIR). As physical extent along our line-of-sight is unknown, consider two possibilities: one in which longest axis measured plane sky (9.4 pc length), it line sight, case take be 17 pc. To...
We present Very Large Array observations of NH3 (1,1) and (2,2) in a sample six infrared-dark clouds (IRDCs) with distances from 2 to 5 kpc. find that ammonia serves as an excellent tracer dense gas IRDCs, showing no evidence depletion, the average abundance these is 8.1 × 10−7. Our consists four IRDCs 24 μm embedded protostars two appear starless. calculate kinetic temperature significant difference between starless star-forming IRDCs. bulk 8 13 K, indicating any or nearby stars clusters do...