2,037 research outputs found
Other Voices piece with a collection of statements by Lawrence Lockman, vice-c
No full textOther Voices piece with a collection of statements by Lawrence Lockman, vice-chairman and press secretary for Concerned Maine Families and author of a weekly column in the Lincoln News
Cataloochee tract 242: J. B. Lockman
No full textThis 42 acre tract 242 in Cataloochee was owned by J. B. Lockman. While, in general, the Great Smoky Mountains region was sparsely populated, the Cataloochee Valley remained an exception. By 1900, the population of Cataloochee had grown to 1,000 residents living in hundreds of log and frame homes. A few historic buildings have been preserved on site, including two churches, a school, several homes, and outbuildings. The North Carolina Park Commission was tasked with purchasing land for the Great Smoky Mountains National Park and people living in Cataloochee were among those displaced. Cataloochee families continue to return for annual reunions. In 2001, the National Park Service re-introduced elk into the valley
A 1200 μm MAMBO Survey of the ELAIS N2 and Lockman Hole East Fields
No full textUsing the MPIfR Max Planck Millimeter Bolometer array (MAMBO) on the IRAM 30m Telescope we have mapped the ELAIS N2 and Lockman Hole East Fields at 1200 μm to a rms noise level of 0.8–1.0 mJy per 11″ beam. The areas surveyed are 326 arcmin² in the ELAIS N2 field and 212 arcmin² in the Lockman Hole1, and cover the 260 arcmin2 previously observed by SCUBA [5]
Infrared array camera (IRAC) imaging of the Lockman Hole
No full textIRAC imaging of a 4′.7 x 4′.7 area in the Lockman Hole detected over 400 galaxies in the IRAC 3.6 and 4.5 μm bands, 120 in the 5.8 μm band, and 80 in the 8.0 μm band in 30 minutes of observing time. Color-color diagrams suggest that about half of these galaxies are at redshifts 0.6 1.3). We also detect IRAC counterparts for six of the seven SCUBA sources and all nine XMM-Newton sources in this area. The detection of the counterparts of the SCUBA sources and galaxies at z > 1.3 demonstrates the ability of IRAC to probe the universe at very high redshifts
Search and modelling of remnant radio galaxies in the LOFAR Lockman Hole field
No full textContext. The phase of radio galaxy evolution after the jets have switched off, often referred to as the remnant phase, is poorly understood and very few sources in this phase are known. Aims: In this work we present an extensive search for remnant radio galaxies in the Lockman Hole, a well-studied extragalactic field. We create mock catalogues of low-power radio galaxies based on Monte Carlo simulations to derive first-order predictions of the fraction of remnants in radio flux limited samples for comparison with our Lockman-Hole sample. Methods: Our search for remnant radio galaxies is based on LOFAR observations at 150 MHz combined with public survey data at higher frequencies. To enhance the selection process, and obtain a more complete picture of the remnant population, we use spectral criteria such as ultra-steep spectral index and high spectral curvature, and morphologre biased toward tinuum: galaxie ical criteria such as low radio core prominence and relaxed shapes to identify candidate remnant radio galaxies. Mock catalogues of radio galaxies are created based on existing spectral and dynamical evolution models combined with observed source properties. Results: We have identified 23 candidate remnant radio galaxies which cover a variety of morphologies and spectral characteristics. We suggest that these different properties are related to different stages of the remnant evolution. We find that ultra-steep spectrum remnants represent only a fraction of our remnant sample suggesting a very rapid luminosity evolution of the radio plasma. Results from mock catalogues demonstrate the importance of dynamical evolution in the remnant phase of low-power radio galaxies to obtain fractions of remnant sources consistent with our observations. Moreover, these results confirm that ultra-steep spectrum remnants represent only a small subset of the entire population ( 50%) when frequencies higher than 1400 MHz are not included in the selection process, and that they are biased towards old ages
The low-frequency size distribution of radio sources in the Lockman Hole
No full textActive galactic nuclei (AGNs) can launch powerful jets that can affect the gas properties in their host galaxies and influence their star formation activity. Depending on their powers and lifetimes and the properties of the surrounding medium, these can remain confined within or close to the galaxy at kiloparsec scales, or grow to giant radio galaxies on megaparsec scales. We measure the projected angular extents of a complete sample of 2,110 radio sources (z 144MHz > 600μJy) using vobs = 144 MHz images over a 6.6 deg2 area of the Lockman Hole field from the International LOw Frequency Array (LOFAR) Telescope (ILT) at resolutions of 6′′, 1.8′′ and 0.45′′. Using these measurements, we derive the first radio source size distribution at a frequency below 200 MHz and present a power-linear size diagram for the objects. We then focus on the 1, 205 sources not identified as star-forming galaxies based on spectral energy distribution (SED) classifications from previous work. These have linear sizes in the range ℓ = 0.7 kpc − 1 Mpc, radio powers in the range P144MHz ≈ 1021 − 1029 W Hz−1, and a linear size distribution in qualitative agreement with that of radio AGNs in the LOFAR Two-metre Sky Survey (LoTSS). While the sample is limited to radio powers P144MHz ≥ 1024 W Hz−1 at higher redshifts due to selection effects, such radio AGNs appear to prefer more compact projected lengths ℓ ≲ 20 kpc, which could indicate that more short-lived, high accretion activity was present in the Early Universe
The Lockman Hole project: LOFAR observations and spectral index properties of low-frequency radio sources
No full textThe Lockman Hole is a well-studied extragalactic field with extensive multi-band ancillary data covering a wide range in frequency, essential for characterizing the physical and evolutionary properties of the various source populations detected in deep radio fields (mainly star-forming galaxies and AGNs). In this paper, we present new 150-MHz observations carried out with the LOw-Frequency ARray (LOFAR), allowing us to explore a new spectral window for the faint radio source population. This 150-MHz image covers an area of 34.7 square degrees with a resolution of 18.6 × 14.7 arcsec and reaches an rms of 160 μJy beam at the centre of the field. As expected for a low-frequency selected sample, the vast majority of sources exhibit steep spectra, with a median spectral index of . The median spectral index becomes slightly flatter (increasing from with decreasing flux density down to S_1_5_0 ∼10 mJy before flattening out and remaining constant below this flux level. For a bright subset of the 150-MHz selected sample, we can trace the spectral properties down to lower frequencies using 60-MHz LOFAR observations, finding tentative evidence for sources to become flatter in spectrum between 60 and 150 MHz. Using the deep, multi-frequency data available in the Lockman Hole, we identify a sample of 100 ultra-steep-spectrum sources and 13 peaked-spectrum sources. We estimate that up to 21 per cent of these could have z > 4 and are candidate high-z radio galaxies, but further follow-up observations are required to confirm the physical nature of these objects
Lockman (Birth, 1896-02-01)
No full textAddress: 561 W. 6th St.770/Pg 17/1896/F W/Russia/Russia/Dr. Amelia J. PriorOriginal record filed in drawer labeled 'LOC-LONGO'
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