相关论文: Testing the Tremaine-Weinberg Method Applied to In…
The grand-design spiral galaxy M51 has long been a crucial target for theories of spiral structure. Studies of this iconic spiral can address the question of whether strong spiral structure is transient (e.g. interaction-driven) or…
We present a prospective work undertaken on Spectro-Polarimetric INterferometry (SPIN). Our theoretical studies suggest that SPIN is a powerful tool for studying the mass loss from early type stars. Based on Monte Carlo simulations, we…
The rich absorption spectra of Sun-like stars are enticing probes for variations in the fine-structure constant, $\alpha$, which gauges the strength of electromagnetism. While individual line wavelengths are sensitive to $\alpha$, they are…
We apply a novel spectral graph technique, that of locally-biased semi-supervised eigenvectors, to study the diversity of galaxies. This technique permits us to characterize empirically the natural variations in observed spectra data, and…
Much of the inner Milky Way's (MW) global rotation and velocity dispersion patterns can be reproduced by models of secularly-evolved, bar-dominated bulges. More sophisticated constraints, including the higher moments of the line-of-sight…
Bulge-disc decomposition is a valuable tool for understanding galaxies. However, achieving robust measurements of component properties is difficult, even with high quality imaging, and it becomes even more so with the imaging typical of…
We use the Tremaine-Weinberg method, adapted to the Milky Way, to measure a pattern speed in OH/IR stars located in the inner MW.
The accuracy and robustness of a simple method to estimate the total mass profile of a galaxy is tested using a sample of 65 cosmological zoom-simulations of individual galaxies. The method only requires information on the optical surface…
Simulated images are essential in algorithm development and instrument testing for optical telescopes. During real observations, images obtained by optical telescopes are affected by spatially variable point spread functions (PSFs), a…
We report on an estimate of the bar pattern speed Omega_p for the low surface brightness spiral galaxy UGC 628. We applied the Tremaine-Weinberg method to high resolution Halpha velocity and integrated emission maps of this dark matter…
We present a method to self-consistently propagate M$_{*}$ and SFR ($\Psi$) uncertainties onto intercept, slope and intrinsic scatter estimates for a simple model of the main sequence of star forming galaxies where $\Psi = \alpha +…
Context: in astronomy, observing large fractions of the sky within a reasonable amount of time implies using large field-of-view (fov) optical instruments that typically have a spatially varying Point Spread Function (PSF). Depending on the…
Weak gravitational lensing provides a unique method to directly measure the distribution of mass in the universe. Because the distortions induced by lensing in the shape of background galaxies are small, the measurement of weak lensing…
Weak gravitational lensing (WL) is a key cosmological probe that requires precise measurement of galaxy images to infer shape distortions, or shear, and constrain cosmology. Accurate estimation of the Point Spread Function (PSF) is crucial…
Star-galaxy separation is a crucial step in creating target catalogues for extragalactic spectroscopic surveys. A classifier biased towards inclusivity risks including spurious stars, wasting fibre hours, while a more conservative…
The existing large scale weak lensing surveys typically reserve the best seeing conditions for a certain optical band to minimize shape measurement errors and maximize the number of usable background galaxies. This is because most popular…
Dedicated 'Stage IV' observatories will soon observe the entire extragalactic sky, to measure the 'cosmic shear' distortion of galaxy shapes by weak gravitational lensing. To measure the apparent shapes of those galaxies, we present an…
Context. Massive stars are predicted to excite internal gravity waves (IGWs) by turbulent core convection and from turbulent pressure fluctuations in their near-surface layers. These IGWs are extremely efficient at transporting angular…
We develop and apply the position angle-only shear estimator of Whittaker et al. (2014) to realistic galaxy images. This is done by demonstrating the method on the simulations of the GREAT3 challenge (Mandelbaum et al. 2014b), which include…
We demonstrate a new multi-wavelength technique for two-dimensional parametric modelling of galaxy surface-brightness profiles, which we have incorporated into the widely used software GALFIT. Our new method, named GALFITM, extends…