1,638 research outputs found
An incident at Kilang: a further note on the death of lieutenant G.F. Phillips
In a recent article dealing with the Tangale Peak or Kilang, as it is called in the local Tangale language, Herrmann JUNGRAITHMAYR presents an account narrated by a Tangale elder about the attempted ascent of that characteristic mountain by a British colonial officer and his subsequent death.1 Kilang mountain is a basaltic cone approximately 1300 m high, about 8 km southwest of Kaltungo, one of the principal settlements of the Tangale people, in southern Bauchi State, northeastern Nigeria. During a research stay at the National Archives in Kaduna in November 1993 I was able to consult a file containing various documents relating to this incident in detail.2 In the following note I present an outline of the events based on the evidence in the colonial records. By doing this I not only intend to shed more light on a tragic event from the very early years of the colonial era. The picture of the circumstances emerging from the investigations of the colonial authorities may serve as a background to the narrative by the Tangale elder presented in JUNGRAITHMAYR's publication
The Cosmic Star-Formation History: The UV finds most
This is a summary of arguments in favor of observing high-redshift star
formation in the UV as presented at the Ringberg meeting in September 2000. The
most rapidly star-forming galaxies are very dusty, easier to detect at 850um
than in the UV, but less rapidly star-forming galaxies are less obscured by
dust and as a result the comparatively faint galaxies that hosted most
high-redshift star formation are easiest to detect in the UV. The correlation
of star-formation rate and dust obscuration implies that extremely luminous
dusty galaxies are usually as bright in the UV as the less luminous dust-free
galaxies, and that any UV survey at a given redshift 0<z<~3 deep enough to
detect the majority of the UV luminosity density will detect the majority of
IR-selected galaxies as well. Little star formation occurs in galaxies that are
completely hidden from UV surveys. I review recent attempts to estimate
star-formation rates for high-redshift galaxies from UV data alone. The
strength of UV surveys is that they detect large numbers of high-redshift
galaxies, even ones that are intrinsically very faint, in large and
representative comoving volumes. The weakness is that star-formation rates are
difficult to estimate for the detected galaxies. IR surveys complement them
perfectly: star-formation rates can be estimated with reasonable confidence,
but only small regions of the sky can be surveyed and only the most luminous
sources can be detected. Multiwavelength cooperation, not conflict, will lead
to future progress in this field.Comment: To be published in "Starburst Galaxies Near and Far", eds. D. Lutz
and L. Tacconi, Springe
Natural environment and settlement in Chonge District, Eastern Muri Mountains, Northeastern Nigeria : an interdisciplinary case study
The craggy and hilly Muri Mountains, which are situated to the north of the Benue Lowlands, are an area with a complex pattern of settlement. This roughly 80 km long and 20 km wide mountainous area is inhabited by about 20 ethnic groups belonging to different language families. The present ethnic and linguistic situation is understood as the result of a complex series of migrations and adaptations to the natural environment. This paper will describe actual movements of settlements and consider certain conditions which may have been relevant in the decision to leave a settlement or choose a new one. The most important conditions will be the accessibility of arable land and/or pasture, accessibility of water, and conditions dependent on the historical and political context such as affording of security and possibility of defence. Therefore an interdisciplinary approach seems to be appropriate to evaluate the natural conditions for settlement and cultivation of the various places from a geographer´s point of view, to interrogate into the historical aspects and motifs of the settlement patterns and migrations with a thorough ethnological background, as well as to gain additional information from a linguistic analysis of toponymes and contact phenomena of the languages spoken in the area
Fundamental Symmetries and Conservation Laws
I discuss recent progress in low-energy tests of symmetries and conservation
laws, including parity nonconservation in atoms and nuclei, electric dipole
moment tests of time-reversal invariance, beta-decay correlation studies, and
decays violating separate (family) and total lepton number.Comment: 11 pages, 5 figures; plenary talk presented at PANIC0
Galaxy Clustering at z~3
Galaxies at very high redshift (z~3 or greater) are now accessible to
wholesale observation, making possible for the first time a robust statistical
assessment of their spatial distribution at lookback times approaching ~90% of
the age of the Universe. This paper summarizes recent progress in understanding
the nature of these early galaxies, concentrating in particular on the
clustering properties of photometrically selected ``Lyman break'' galaxies.
Direct comparison of the data to predictions and physical insights provided by
galaxy and structure formation models is particularly straightforward at these
early epochs, and results in critical tests of the ``biased'', hierarchical
galaxy formation paradigm.Comment: Presented at Royal Society Discussion Meeting, March 1998, "Large
Scale Structure in the Universe", 14 pages LaTeX, 7 ps figures, uses
rspublic.sty (included
A Steep Faint-End Slope of the UV Luminosity Function at z~2-3: Implications for the Global Stellar Mass Density and Star Formation in Low Mass Halos
We use the deep ground-based optical photometry of the Lyman Break Galaxy
(LBG) Survey to derive robust measurements of the faint-end slope (alpha) of
the UV LF at redshifts 1.92000 spectroscopic
redshifts and ~31000 LBGs in 31 spatially-independent fields over a total area
of 3261 arcmin^2. These data allow us to select galaxies to 0.07L* and 0.10L*
at z~2 and z~3, respectively. A maximum likelihood analysis indicates steep
values of alpha(z=2)=-1.73+/-0.07 and alpha(z=3)=-1.73+/-0.13. This result is
robust to luminosity dependent systematics in the Ly-alpha equivalent width and
reddening distributions, is similar to the steep values advocated at z>4, and
implies that ~93% of the unobscured UV luminosity density at z~2-3 arises from
sub-L* galaxies. With a realistic luminosity dependent reddening distribution,
faint to moderately luminous galaxies account for >70% and >25% of the
bolometric luminosity density and present-day stellar mass density,
respectively, when integrated over 1.9<z<3.4. We find a factor of 8-9 increase
in the star formation rate density between z~6 and z~2, due to both a
brightening of L* and an increasing dust correction proceeding to lower
redshifts. The previously observed discrepancy between the integral of the star
formation history and stellar mass density measurements at z~2 may be
reconciled by invoking a luminosity dependent reddening correction to the star
formation history combined with an accounting for the stellar mass contributed
by UV-faint galaxies. The steep and relatively constant alpha of the UV LF at
z>2 contrasts with the shallower value inferred locally, suggesting that the
evolution in the faint-end slope may be dictated simply by the availability of
low mass halos capable of supporting star formation at z<2. [Abridged]Comment: 29 pages, 15 figures, 7 tables; accepted for publication in Ap
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