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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…
XMM-Newton observations of the eclipsing polar V2301 Oph
Cropper, Mark; Ramsay, Gavin
We present XMM-Newton observations of the eclipsing polar V2301 Oph which cover nearly 2.5 binary orbital cycles and two eclipses. This polar is believed to have the lowest magnetic field strength (7 MG) of any known polar. We find evidence for structure in the X-ray eclipse profile which shows a `standstill' feature lasting 26 +/- 4 s. This allow…