Search Publications
The effect of dust on Tremaine-Weinberg measurements
Gerssen, Joris; Debattista, Victor P.
We investigate the effect of dust on the observed rotation rate of a stellar bar. The only direct way to measure this quantity relies on the Tremaine & Weinberg (TW) method which requires that the tracer satisfies the continuity equation. Thus, it has been applied largely to early-type barred galaxies. We show using numerical simulations of ba…
η Muscae: a young detached binary with two identical components
Demircan, O.; Bakış, V.; Eker, Z. +1 more
High-resolution (λ/dλ ~ 41000) echelle spectra of the multiple system η Muscae were analysed. Precise spectroscopic orbital elements of the close pair η Muscae-A were obtained by means of two techniques; cross-correlation and spectral disentangling. The updated light elements of the close pair were derived using new photometric and spectroscopic d…
Orbital solution and fundamental parameters of σ Scorpii
Tuthill, P. G.; Davis, J.; Tango, W. J. +2 more
The first orbital solution for the spectroscopic pair in the multiple star system σ Scorpii, determined from measurements with the Sydney University Stellar Interferometer, is presented. The primary component is of β Cephei variable type and has been one of the most intensively studied examples of its class. The orbital solution, when combined wit…
The sizes of disc galaxies in intermediate-redshift clusters
Milvang-Jensen, B.; Aragón-Salamanca, A.; Bamford, S. P.
We examine how the location of star formation within disc galaxies depends on environment at intermediate redshift. This is achieved by comparing emission-line (rem) and rest-frame B-band (rB) scalelengths for matched samples of 50 field and 19 cluster, star-forming, disc galaxies, with 0.25 <= z <= 1.0 and MB
A new superwind galaxy: XMM-Newton observations of NGC 6810
Strickland, David K.
We present the first imaging X-ray observation of the highly inclined (i = 78°) Sab Seyfert 2 galaxy NGC 6810 using XMM-Newton, which reveals soft X-ray emission that extends out to a projected height of ~7 kpc away from the plane of the galaxy. The soft X-ray emission beyond the optical disc of the galaxy is most plausibly extraplanar, although i…
A longer XMM-Newton look at I Zwicky - 1. Distinct modes of X-ray spectral variability
Brandt, W. N.; Costantini, E.; Fabian, A. C. +1 more
The short-term spectral variability of the narrow-line Seyfert 1 galaxy I Zwicky 1 (I Zw 1) as observed in an 85ks XMM-Newton observation is discussed in detail. I Zw 1 shows distinct modes of variability prior to and after a flux dip in the broad-band light curve. Before the dip the variability can be described as arising from changes in shape an…
XMM-Newton X-ray observations of the Wolf-Rayet binary system WR 147
Schmutz, W.; Güdel, M.; Skinner, S. L. +1 more
We present results of an ~20-ks X-ray observation of the Wolf-Rayet (WR) binary system WR 147 obtained with XMM-Newton. Previous studies have shown that this system consists of a nitrogen-type WN8 star plus an OB companion whose winds are interacting to produce a colliding wind shock. X-ray spectra from the pn and MOS detectors confirm the high ex…
Steepened inner density profiles of group galaxies via interactions: an N-body analysis
King, Lindsay J.; Fellhauer, Michael; Dobke, Benjamin M.
We continue to see a range of values for the Hubble constant obtained from gravitationally lensed multiple image time-delays when assuming an isothermal lens despite a robust value from the Hubble Space Telescope (HST) key project (72 +/- 8 kms-1 Mpc-1). One explanation is that there is a variation in Hubble constant values d…
The mass function of ω Centauri down to 0.15 Msolar
Bellazzini, M.; Ferraro, F. R.; Sollima, A.
By means of deep FORS1/VLT and ACS/Hubble Space Telescope observations of a wide area in the stellar system ω Cen we measured the luminosity function of main-sequence stars down to R = 22.6 and IF814W = 24.5. The luminosity functions obtained have been converted into mass functions and compared with analytical initial mass functions (IM…
The SCUBA HAlf Degree Extragalactic Survey (SHADES) - V. Submillimetre properties of near-infrared-selected galaxies in the Subaru/XMM -Newton deep field
Smail, I.; Ivison, R. J.; Clements, D. L. +21 more
We have studied the submillimetre (submm) properties of the following classes of near-infrared-selected (NIR-selected) massive galaxies at high redshifts: BzK-selected star-forming galaxies (BzKs); distant red galaxies (DRGs); and extremely red objects (EROs). We used the SCUBA HAlf Degree Extragalactic Survey (SHADES), the largest uniform submm s…