2,620 research outputs found

    Howden Moss: a study of vegetational history in Upper Teesdale

    Get PDF
    The peat deposits at Howden Moss, Upper Teesdale, have been examined stratigraphically and pollen analytically. The present state of the bog in described and pollen diagrams are presented for three sites. The results show that peat formation had begun by the early post-glacial period, zone V, and growth apparently continued up to the present time. The area was colonised by birch trees early in its development. Open birchwood persisted on the site during the expansion of mixed oak forest into the valley bottom. This dichotomous situation continued until the birch wood on the fell was replaced by blanket bog communities. The late-glacial rolict flora which is associated with some sites in Upper Teesdale is not found at Howden Moss. The pollen record provides no evidence for its past existence in the area

    The HI Chronicles of LITTLE THINGS BCDs: Evidence for External Perturbations in the Morphology and Kinematics of Haro 29 and Haro 36

    Full text link
    We analyze high angular and velocity resolution HI-line data of two LITTLE THINGS (1) blue compact dwarfs (BCDs): Haro 29 and Haro 36. Both of these BCDs are disturbed morphologically and kinematically. Haro 29's HI data reveal a kinematic major axis that is offset from the optical major axis, and a disturbed outer HI component, indicating that Haro 29 may have had a past interaction. Position-velocity diagrams of Haro 36 indicate that it has two kinematically separate components at its center and a likely tidal tail in front of the galaxy. We find that Haro 36 most likely had an interaction in the past, is currently interacting with an unknown companion, or is a merger remnant. (1) "Local Irregulars That Trace Luminosity Extremes The HI Nearby Galaxy Survey" http://www2.lowell.edu/users/dah/littlethings/index.htmlComment: To be published in The Astronomical Journa

    HI observations of dwarf galaxies out to a distance of 50 Mpc

    Get PDF
    Here we report our preliminary findings from an HI search for dwarf galaxies in three environmentally distinct regions of the sky: a galactic void, a galactic cluster, and an interaction field. This study is sensitive at the 5(sigma) level to hydrogen masses as low as 5 x 10(exp 5) solar mass. We have made three possible detections of previously uncatalogued objects: one in the void field, and two in the cluster field. Reduction of the interaction field is in progress

    The environments of Markarian galaxies

    Get PDF
    The extensively studied Markarian sample of 1500 ultraviolet excess galaxies contains many Seyfert, starburst, and peculiar galaxies. Using the 20 minute V plates obtained for the construction of the Hubble Space Telescope Guide Star Catalog, the authors investigated the morphologies of the Markarian galaxies and the environments in which they are located. The relationship between the types of nuclear activity and the morphologies and environments of the Markarian galaxies is discussed. The authors conclude that the type of nuclear activity present in the galaxies of the Markarian sample is not dependent on either the morphology or the local environment of the galaxy. This is not to imply that nuclear activity per se is not influenced by the environment in which the nucleus is located. Rather the type of nuclear activity (at least in the Markarian population) does not appear to be determined by the environment

    Falling in Acute Mental Health Settings for Older People : Who falls, where, when and why?

    Get PDF
    Copyright: © 2014 Dickinson A et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Falls, slips and trips are a major patient safety concern in hospital settings accounting for 26 per cent of all reported patient safety incidents in England. Mental health conditions and their treatments add further to fall risk but we have little information regarding who falls, where and when within mental health settings. Methods: This paper presents an overview of the pattern of falls by older patients within an in-patient mental health setting in the South of England using routine records completed by staff when a fall occurs. 920 fall reports over three years were analysed, and 7 focus groups were undertaken with ward staff to explore how staff understood falls and their experiences of using the falls reporting system. Results: In terms of diagnosis 40% of fallers had a primary functional diagnosis, 46% an organic mental health diagnosis (14% non-specific diagnosis), average age was 81.7 years (range 59 to 99 years; SD 8.3) and 57% were female. Approximately one quarter, 27%, of falls were observed by staff. Falls were not evenly distributed across either day of week or time of day, with peak times for falls on Tuesday and Saturday and morning (7-8 and 9-10am) and subsidiary peaks between noon and 1pm and early evening (5-6pm). Almost half of falls occurred in private spaces in the ward such as bedrooms, and 42% in public spaces such as sitting rooms. However 60% of falls in public spaces were unseen. Reporting in these settings was problematic for staff and patients were sometimes described as placing themselves on the floor as a consequence of their mental health condition. The average time to first fall was 5 weeks. Conclusions: Routine mapping of falls could be undertaken at ward and organization level and contribute to better understanding of the local factors contributing to falls. Exploring incident report data in focus groups with staff helped us and them to interpret the data and to understand some of the decision making staff engage in everyday when reporting falls.Peer reviewedFinal Published versio

    The HI Chronicles of LITTLE THINGS BCDs II: The Origin of IC 10's HI Structure

    Full text link
    In this paper we analyze Very Large Array (VLA) telescope and Green Bank Telescope (GBT) atomic hydrogen (HI) data for the LITTLE THINGS(1) blue compact dwarf galaxy IC 10. The VLA data allow us to study the detailed HI kinematics and morphology of IC 10 at high resolution while the GBT data allow us to search the surrounding area at high sensitivity for tenuous HI. IC 10's HI appears highly disturbed in both the VLA and GBT HI maps with a kinematically distinct northern HI extension, a kinematically distinct southern plume, and several spurs in the VLA data that do not follow the general kinematics of the main disk. We discuss three possible origins of its HI structure and kinematics in detail: a current interaction with a nearby companion, an advanced merger, and accretion of intergalactic medium. We find that IC 10 is most likely an advanced merger or a galaxy undergoing accretion. 1:Local Irregulars That Trace Luminosity Extremes, The HI Nearby Galaxy Survey; https://science.nrao.edu/science/surveys/littlethingsComment: 36 pages, 17 figures, accepted for publication in The Astronomical Journa

    DDO 88: A Galaxy-Sized Hole in the Interstellar Medium

    Full text link
    We present an HI and optical study of the gas-rich dwarf irregular galaxy DDO 88. Although DDO 88's global optical and HI parameters are normal for its morphological type, it hosts a large (3 kpc diameter) and unusually complete ring of enhanced HI emission. The gas ring is located at approximately one-third of the total HI radius and one-half the optically-defined Holmberg radius, and contains 30% of the total HI of the galaxy. The ring surrounds a central depression in the HI distribution, so it may be a shell formed by a starburst episode. However, the UBV colors in the HI hole are not bluer than the rest of the galaxy as would be expected if an unusual star-forming event had taken place there recently, but there is an old (~1-3 Gyr), red cluster near the center of the hole that is massive enough to have produced the hole in the HI. An age estimate for the ring, however, is uncertain because it is not observed to be expanding. An expansion model produces a lower estimate of 0.5 Gyr, but the presence of faint star formation regions associated with the ring indicate a much younger age. We also estimate that the ring could have dispersed by now if it is older than 0.5 Gyr. This implies that the ring is younger than 0.5 Gyr. A younger age would indicate that the red cluster did not produce the hole and ring. If this ring and the depression in the gas which it surrounds were not formed by stellar winds and supernovae, this would indicate that some other, currently unidentified, mechanism is operating.Comment: 44 pages; 16 figures. To appear in AJ, January 2005. Available from ftp.lowell.edu, cd pub/dah/papers/d88 and http://www.fiu.edu/~simpsonc/d8

    VII Zw 403: H I structure in a blue compact dwarf galaxy

    Get PDF
    ‘In these times, during the rise in the popularity of institutional repositories, the Society does not forbid authors from depositing their work in such repositories. However, the AAS regards the deposit of scholarly work in such repositories to be a decision of the individual scholar, as long as the individual's actions respect the diligence of the journals and their reviewers.’ Original article can be found at : http://iopscience.iop.org/ Copyright American Astronomical SocietyWe present optical (UBVJ), ultraviolet (FUV, NUV), and high-resolution atomic hydrogen (H I) observations of the nearby blue compact dwarf (BCD), VII Zw 403. We find that VII Zw 403 has a relatively high H I mass-to-light ratio for a BCD. The rotation velocity is nominally 10-15 km s(-1), but rises to similar to 20 km s(-1) after correction for the similar to 8-10 km s(-1) random motions present in the gas. The velocity field is complex, including a variation in the position angle of the major axis going from the northeast to the southwest parts of the galaxy. Our high-resolution Hi maps reveal structure in the central gas, including a large, low-density Hi depression or hole between the southern and northern halves of the galaxy, coincident with an unresolved X-ray source. Although interactions have been proposed as the triggering mechanism for the vigorous star formation occurring in BCDs, VII Zw 403 does not seem to have been tidally triggered by an external interaction, as we have found no nearby possible perturbers. It also does not appear to fall in the set of galaxies that exhibit a strong central mass density concentration, as its optical scale length is large in comparison to similar systems. However, there are some features that are compatible with an accretion event: optical/Hi axis misalignment, a change in position angle of the kinematic axis, and a complex velocity field.Peer reviewe
    corecore