M. J. Barlow
A5016300535- Stellar, planetary, and galactic studies
- Astrophysics and Star Formation Studies
- Astronomy and Astrophysical Research
- Astro and Planetary Science
- Gamma-ray bursts and supernovae
- Astronomical Observations and Instrumentation
- Astrophysical Phenomena and Observations
- Astrophysics and Cosmic Phenomena
- Atmospheric Ozone and Climate
- Spectroscopy and Laser Applications
- Galaxies: Formation, Evolution, Phenomena
- Atomic and Molecular Physics
- History and Developments in Astronomy
- Calibration and Measurement Techniques
- Molecular Spectroscopy and Structure
- Solar and Space Plasma Dynamics
- Pulsars and Gravitational Waves Research
- Space Exploration and Technology
- High-pressure geophysics and materials
- Geological Modeling and Analysis
- Superconducting and THz Device Technology
- Planetary Science and Exploration
- Geochemistry and Geologic Mapping
- Advanced Chemical Physics Studies
- Adaptive optics and wavefront sensing
University College London
2015-2024
University College Lahore
2022-2023
Geoscience Australia
2020-2022
Hamilton College
2018
UNSW Sydney
2011-2015
Australian Defence Force Academy
2015
UCL Australia
1995-2011
Japan External Trade Organization
2011
Laboratoire d’Astrophysique de Marseille
2010
Château Gombert
2010
The Spectral and Photometric Imaging Receiver (SPIRE), is the Herschel Space Observatory`s submillimetre camera spectrometer. It contains a three-band imaging photometer operating at 250, 350 500 microns, an Fourier Transform Spectrometer (FTS) which covers simultaneously its whole range of 194-671 microns (447-1550 GHz). SPIRE detectors are arrays feedhorn-coupled bolometers cooled to 0.3 K. has field view 4' x 8', observed in three spectral bands. Its main mode scan-mapping, whereby...
We present the first results from science demonstration phase for Hi-GAL survey, <i>Herschel<i/> key program that will map inner Galactic plane of Milky Way in 5 bands. outline our data reduction strategy and some highlights on two observed 2° × tiles approximately centered at <i>l<i/> = 30° 59°. The regions are extremely rich intense highly structured extended emission which shows a widespread organization filaments. Source SEDs can be built hundreds objects fields, physical parameters...
A unified model is presented for the radio and infrared spectrum of early-type stars surrounded by a gaseous ionized envelope resulting from mass loss. The cases uniform loss (i) at constant velocity, (ii) with accelerative effects taken into account, are treated. It shown that free–free spectra predicted to be form |$S_\nu \propto \nu^{0.6}$| except (typically) in near where will become flatter. Various which may cause deviation 0.6 spectral index considered. Finally, it how flux densities...
Hi-GAL, the Herschel infrared Galactic Plane Survey, is an Open Time Key Project of Space Observatory. It will make unbiased photometric survey inner plane by mapping a 2° wide strip in longitude range ∣l∣ < 60° five wavebands between 70 μm and 500 μm. The aim Hi-GAL to detect earliest phases formation molecular clouds high-mass stars use optimum combination wavelength coverage, sensitivity, strategy, speed deliver homogeneous census star-forming regions cold structures interstellar medium....
We present spectrophotometric observations of a sample 80 southern galactic planetary nebulae (PN), and derive elemental abundances for 68 objects, supplementing the optical with UV data in 25 cases. define Type I PN as those objects that have experienced envelope-burning conversion to nitrogen dredgedup primary carbon. Such are recognised by their having exceed total C + N abundance H II regions same galaxy. In our own galaxy, this criterion corresponds N/O > 0.8. current sample, 11 0.8...
The INT Photometric Halpha Survey of the Northern Galactic Plane (IPHAS) is a 1800 square degrees CCD survey northern Milky Way spanning latitude range -5 < b +5 (degrees) and reaching down to r' ~ 20 (10-sigma). It may increase number known emission line sources by an order magnitude. Representative observations assessment point-source data from IPHAS, now underway, are presented. obtained Wide Field Camera images in narrow-band, Sloan i' broad-band, filters. We simulate IPHAS (r' -...
view Abstract Citations (478) References (63) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Terminal Velocities for a Large Sample of O Stars, B Supergiants, and Wolf-Rayet Stars Prinja, Raman K. ; Barlow, M. J. Howarth, Ian D. It is argued that easily measured, reliable estimates terminal velocities early-type stars are provided by the central velocity asymptotically approached narrow absorption features violet limit zero residual intensity in saturated P...
The large amount of dust produced by this supernova may help explain the observed in young galaxies.
Thousands of exoplanets have now been discovered with a huge range masses, sizes and orbits: from rocky Earth-like planets to large gas giants grazing the surface their host star. However, essential nature these remains largely mysterious: there is no known, discernible pattern linking presence, size, or orbital parameters planet its parent We little idea whether chemistry linked formation environment, type star drives physics planet's birth, evolution. ARIEL was conceived observe number...
Thermal images of cold dust in the Central Molecular Zone Milky Way, obtained with far-infrared cameras on board Herschel satellite, reveal a ∼3 × 107 M☉ ring dense and clouds orbiting Galactic center. Using simple toy model, an elliptical shape having semi-major axes 100 60 pc is deduced. The major axis this inclined by about 40° respect to plane sky oriented perpendicular Bar. appears trace system stable x2 orbits predicted for barred potential. Sgr A⋆ displaced geometrical center symmetry...
The Herschel Reference Survey is a guaranteed time key project and will be benchmark study of dust in the nearby universe. survey complement number other projects including large cosmological surveys that trace distant We use to produce images statistically-complete sample 323 galaxies at 250, 350 500 micron. volume-limited, containing sources with distances between 15 25 Mpc flux limits K-band minimize selection effects associated young high-mass stars introduce stellar mass. spans whole...
(Abridged) We present the first public release of high-quality data products (DR1) from Hi-GAL, {\em Herschel} infrared Galactic Plane Survey. Hi-GAL is keystone a suite continuum surveys near-IR to radio, and covers five wavebands at 70, 160, 250, 350 500 micron, encompassing peak spectral energy distribution cold dust for 8 < T 50K. This inner Milky Way in longitude range 68{\deg} > l -70{\deg} |b|<1{\deg} latitude strip. Photometric maps have been produced with ROMAGAL pipeline, that...
The VST Photometric Halpha Survey of the Southern Galactic Plane and Bulge (VPHAS+) is surveying southern Milky Way in u, g, r, i at 1 arcsec angular resolution. Its footprint spans latitude range -5 < b +5 all longitudes south celestial equator. Extensions around Centre to latitudes +/-10 bring much Bulge. This ESO public survey, begun on 28th December 2011, reaches down 20th magnitude (10-sigma) will provide single-epoch digital optical photometry for 300 million stars. observing strategy...
The Dwarf Galaxy Survey (DGS) program is studying low-metallicity galaxies using 230h of far-infrared (FIR) and submillimetre (submm) photometric spectroscopic observations the Herschel Space Observatory draws to this a rich database wide range wavelengths tracing dust, gas stars. This sample 50 includes largest metallicity achievable in local Universe including lowest (Z) galaxies, 1/50 Zsun, spans 4 orders magnitude star formation rates. survey designed get handle on physics interstellar...
The nearby Supernova 1987A was accompanied by a burst of neutrino emission, which indicates that compact object (a neutron star or black hole) formed in the explosion. There has been no direct observation this object. In work, we observe supernova remnant with JWST spectroscopy finding narrow infrared emission lines argon and sulphur. line is spatially unresolved blueshifted velocity relative to rest frame. We interpret as gas illuminated source ionizing photons located close center...
We have obtained deep optical spectra of the planetary nebula NGC 6153, both along its minor axis and by uniformly scanning a long slit across whole nebula. The scanned spectra, when combined with nebular total Hβ flux, yield integrated fluxes for all lines (∼400) in our which are rich strong recombination from C, N, O Ne ions. A weak viλ3811 emission line central star has been detected, suggesting that nucleus 6153 hydrogen-deficient surface. data, together ISO LWS 43–197 μm spectrum...
We present a quantitative classification scheme for carbon and oxygen sequence Wolf-Rayet stars. Our uses new high-quality optical A AT INT observations of 20 stars which we provide narrow-band photometry estimates interstellar reddenings. In increasing order excitation, our spectral classes range from WC11 to WC4 WolfRayet with dominant line visual spectrum, subsequently WO4 WO1 those predominantly lines. refine existing WC WO schemes incorporate higher lower excitation features. Both...
SPIRE, the Spectral and Photometric Imaging REceiver, is <i>Herschel<i/> Space Observatory's submillimetre camera spectrometer. It contains a three-band imaging photometer operating at 250, 350 500 <i>μ<i/>m, an Fourier-transform spectrometer (FTS) covering 194–671 <i>μ<i/>m (447-1550 GHz). In this paper we describe initial approach taken to absolute calibration of SPIRE instrument using combination emission from telescope itself modelled continuum solar system objects other astronomical...
The study of photoionized environments is fundamental to many astrophysical problems. Up the present most photoionization codes have numerically solved equations radiative transfer by making extreme simplifying assumption spherical symmetry. Unfortunately very few real astronomical nebulae satisfy this requirement. To remedy these shortcomings, a self-consistent, three-dimensional code has been developed using Monte Carlo techniques. code, mocassin, designed build realistic models having...
Absolutely calibrated versions of realistic model atmosphere calculations for Sirius and Vega by Kurucz (1991) are presented used as a basis to offer new absolute calibration infrared broad narrow filters. In-band fluxes obtained defined be zero magnitude at all wavelengths shortward 20 microns. Existing photometry is differentially establish an scale the model, yielding angular diameter within 1 sigma mean determined interferometrically Hanbury Brown et al. (1974). The use primary stellar...
Vega-like stars are main-sequence that exhibit excess infrared emission due to dust grains which believed be distributed in circumstellar discs. To facilitate modelling of the properties discs and their constituent grains, we have assembled a new observational database for large sample candidate systems, comprises UBVRI optical photometry, JHKLL'M near-IR mid-IR spectra, mm/submm-wave photometry.
We report on an analysis of the gas and dust budget in interstellar medium (ISM) Large Magellanic Cloud (LMC). Recent observations from Spitzer Space Telescope enable us to study mid-infrared excess asymptotic giant branch (AGB) stars LMC. This is first time we can quantitatively assess input AGB over a complete galaxy, fully based observations. The integrated mass-loss rate all intermediate high carbon-rich candidates LMC 8.5x10^-3 solar mass per year, up 2.1x10^-2 year. number could be...
We present late-time optical and mid-infrared observations of the Type II supernova 2003gd in galaxy NGC 628. Mid-infrared excesses consistent with cooling dust ejecta are observed 499 to 678 days after outburst accompanied by increasing extinction growing asymmetries emission-line profiles. Radiative-transfer models show that up 0.02 solar masses has formed within ejecta, beginning as early 250 outburst. These formation can be efficient massive-star supernovae could have been major...
Noble gas molecules have not hitherto been detected in space. From spectra obtained with the Herschel Space Observatory, we report detection of emission 617.5 GHz and 1234.6 J = 1-0 2-1 rotational lines {36}ArH^+ at several positions Crab Nebula, a supernova remnant known to contain both H2 regions enhanced ionized argon emission. {36}Ar is believed originated from explosive nucleosynthesis massive stars during core-collapse events. Its product such event, confirms this expectation. The...