Advanced search    

Search: authors:"S. N. Kemp"

21 papers found.
Use AND, OR, NOT, +word, -word, "long phrase", (parentheses) to fine-tune your search.

Results of the digital co-addition of thirteen Schmidt films of the Virgo cluster of galaxies

We have digitally co-added APM scans of 13 Kodak TechPan films of the SE region of the Virgo cluster of galaxies. The field of the R-band films combined with the resolution of arcsec pixel-1 results in data file sizes of about 222 MBytes. The 13 scanned films have been aligned, co-added, corrected for vignetting effects and cleaned of stellar features. To illustrate the...

The emission and kinematic structures of the bipolar planetary nebula M 1-8

We have undertaken echelle spectroscopy and narrow-band line imaging of the bipolar planetary nebula M 1-8. This has permitted us to map the outflow in [N ii]λλ 6548+6583 Å, Hα, and in thev= 1–0 S(1) transition of H2 at λ 2.122 μm. It has also permitted us to acquire high-resolution spectra for [N ii]λ 6583 Å, Hα and He iiλ 6560 Å. Our observations support the results of a...

Near-infrared mapping of comet 73P/Schwassmann–Wachmann 3-B

Comet 73P/Schwassmann–Wachmann 3 made a close approach to Earth in the first half of 2006, during which its nucleus was observed to disintegrate into 80 or more fragments. We report the results of infrared mapping of fragment B on May 12, during which images were obtained in J, H and K′. The observations indicate the presence of strong variations in colour as a function of...

Spectroscopy of six highly evolved Abell planetary nebulae

We have undertaken visual spectroscopy of the highly evolved planetary nebulae (PNe) A8, A13, A62, A72, A78 and A83 over a wavelength range 4330 < λ < 6830Å. This permits us to specify relative line intensities in various sectors of the nebular shells, and to investigate the variation of emission as a function of radius. We determine that the spectrum of the central star of A78...

High-resolution spectroscopy of the Seyfert galaxy Mrk 595 in the direction of the Cohen H i high-velocity stream

S. N. Kemp 0 B. Bates 0 0 Department of Pure and Applied Physics, The Queen's University of Belfast , Belfast BT7 1NN A B S T R A C T We have obtained a spectrum of the Na D lines of the Seyfert

BVRI photometric analysis for the galaxy group NGC 4410

We present a BVRI CCD (Charge Coupled Device) surface photometry analysis of the galaxy group NGC 4410, which contains four galaxies in interaction. Along with our photometric study, we show residual images (after subtracting isophotal models) and unsharp masked images to uncover any hidden structures in this system of galaxies; we have also performed a two-dimensional bulge-disk...

The common halo and tidal features of the interacting pair of galaxies NGC 5215a and b revealed by the co-addition of eight Schmidt plates

The interacting pair of galaxies NGC 5215a and b has been investigated by means of a co-added data array of APM scans of eight Schmidt plates. The pair is found to be embedded in a common halo, and each member has a tidal tail which trails the rotation of the core region. Distortions of the isophotes of the pair confirm the tidal interaction between the two galaxies. A detached...

The 0.6 Mpc halo of the cD galaxy (MCG 05–33–002) in the cluster Abell 3571 revealed by the co-addition of eight Schmidt plates

Eight IIIaJ sky-limited plates of the same field taken with the UK 1.2-m Schmidt telescope have been scanned by the APM machine and digitally co-added. The field contains the cD galaxy MCG 05–33–002, the central galaxy in the cluster A3571. A giant faint halo, of dimensions $\sim 600 \times 200\enspace \text {kpc}$, has been found to envelop most of the cluster. It is estimated...

Further optical and UV spectroscopy of stars in the direction of the Riegel & Crutcher cold cloud

at b = _10 (Bates et al. 1992), very weakly at b = -15 (Montgomery et al. 1993) and, optically, in the direction of the globular cluster M55 (diameter 89K 1096 S. N. Kemp, B. Bates and N. C. Hambly 0 1 ... . However, if, for example, only half the CH was associated with the CH +, it would not greatly affect our suggestions for the most appropriate model parameters. 89K 1100 S. N. Kemp, B. Bates and N. C. Hambly

Optical and UV spectroscopy of stars in the direction of the Riegel & Crutcher cold cloud

Optical and UV spectral data are presented for the stars HD 165202, 168708 which lie in the direction of the Riegel & Crutcher cold cloud. These observations complement our earlier studies in which high-resolution H I profiles mapped the cold cloud in self-absorption (Montgomery et al.). HD 165202 lies in a direction close to where we observe a maximum H I self-absorption column...

A study of the behaviour of the Na I/K I column density ratio in the interstellar medium using the Na ultraviolet doublet

Here we make a new study of the behaviour of the Na I/K I column density ratio in the interstellar medium, using a sample of new observations of 28 stars obtained at the Nordic Optical Telescope (NOT) in 1996 and 1997, and previously published observations (obtained by some of the authors) of 21 stars. The sightlines cover a range of distances and directions, including into the...

Results of the digital co-addition of thirteen Schmidt films of the Virgo cluster of galaxies

We have digitally co-added APM scans of 13 Kodak TechPan films of the SE region of the Virgo cluster of galaxies. The field of the R-band films combined with the resolution of arcsec pixel-1 results in data file sizes of about 222 MBytes. The 13 scanned films have been aligned, co-added, corrected for vignetting effects and cleaned of stellar features. To illustrate the...

Mass motions in the atmospheres of red giants in the globular clusters M55 and M13

We present Na D and Hα stellar line profiles for a sample of 19 stars in M55 and M13, in a search for spectral features indicative of mass motions in the atmospheres of red giants. We combine the observations of the stars in these two clusters with those made previously for stars in ω Cen, M22 and M4 to give a total sample of 63 globular cluster red giants. From this total sample...

Observations of differential reddening towards the globular cluster M4

Differential reddening across the globular cluster M4 is studied using KI column density measurements towards 16 stars in the cluster and the empirical N(KI)– E(B-V) relationship presented by Chaffee & White for the Sco-Oph region. A value of E(B-V) towards each star is obtained, which reveals the existence of a patchy reddening variation across the cluster face. We report a...

High-resolution optical observations of two early-type stars towards the high-velocity cloud Complex M

High-resolution optical spectra of the early-type stars HD 93521 and BD +38° 2182, which lie only 27 arcmin apart on the sky in the direction of the high-velocity cloud (HVC) Complex M, reveal the presence of weak HVC absorption in the Ca K line towards BD +38° 2182, with a velocity of $V_\textrm{LSR}=-96.0\pm1.5 \enspace\text {km}\enspace\text s^{-1}$ and an equivalent width $W_...

Optical and UV spectroscopy towards stars in the direction of the Cohen high-velocity H I stream

We present high-resolution, high signal-to-noise ratio optical spectra and UV spectra obtained with IUE for several stars that lie within and adjacent to the Cohen high-velocity (HV) stream, which is considered by Cohen to lie within 300 pc. From spectral classifications, published photometry and LTE model atmosphere analysis of our stellar spectra, the programme stars are shown...

IUE and H I observations of gas components towards HD 174632⋆

IUE spectra of gas components towards the nearby star HD 174632 are reported, together with λ21-cm H I emission profiles obtained in the direction of the star and at several neighbouring positions some 1° from the star. These new observations reveal a far more complex velocity structure of the interstellar gas than that reported through optical spectroscopy by Crawford, with...

On the parallax of WD 0346+246: a halo white dwarf candidate

We present a parallax measurement for the very cool degenerate WD 0346+246, the serendipitous discovery of which was reported by Hambly et al. We find an absolute parallax of 36±5 mas, yielding a distance estimate of 28±4 pc. The resulting absolute visual magnitude of the object is MV=16.8±0.3, making it the second-lowest luminosity white dwarf currently known. We use the...

Radio H I and optical absorption-line spectra of an intermediate-velocity cloud in the general direction of the M15 globular cluster

Using H I spectra obtained with the Lovell telescope (FWHM ∼ 12 arcmin) we present maps showing the H I distribution and velocity structure of an intermediate-velocity cloud (IVC; vLSR ∼ 70 km s−1) which is observed in the general direction of the globular cluster M15. The gas is shown to be clumpy in nature and we examine its position and velocity structure. The IVC is detected...

Optical and infrared photometry of the Type IIn SN 1998S: days 11–146

A. Fassia 3 w W. P. S. Meikle 3 W. D. Vacca 1 S. N. Kemp 0 5 N. A. Walton 7 D. L. Pollacco 6 S. Smartt 7 A. Oscoz 5 A. Arago n-Salamanca 4 S. Bennett 9 T. G. Hawarden 8 A. Alonso 5 D. Alcalde 5 A