584 research outputs found
Between Fiction and Documentary: Dangerous Liaisons and the Self-Reflexive Film
As the two primary modes of filmic representation, fiction and documentary have long been separated by their distinct associations with subjectivity and objectivity respectively. Documentary film, with its ties to lived reality, has been especially hampered by a too direct connection with objectivity. Regarding the documentary film\u27s representation of actuality, there is a tendency for the authority behind the construction of the documentary image to go unexplored and unquestioned when the documentary subject is thought to be objectively represented. Neither fiction nor documentary image are likely to be destabilized when each mode neglects to recognize its connection to an alternative manner of representation—non-fiction for fiction film and vice versa. While the acknowledgment of the intimate relationship between fiction and non-fiction has received much attention over the past fifteen years (particularly in the growing area of documentary film studies), further critical analysis is still needed.
In order to more fully understand the relationship between fiction and non-fiction modes of representation in film, this study is divided into a creative project (in the form of a documentary film made by the author) and a written scholarly project which analyzes a range of fiction and documentary films. Included in the dissertation is a chapter on 25 Fictions, the author\u27s forty-minute video that depicts some of the fictions which make up historic 25th Street in Ogden, Utah. Those portions of Chapter V that deal with 25 Fictions are in italics. The other films discussed include, for instance, Gillo Pontecorvo\u27s The Battle of Algiers, Lars von Trier\u27s Breaking the Waves, Nicholas Barker\u27s Unmade Beds, and Stephen Earnhart\u27s Mule Skinner Blues. Each film\u27s analysis traces the presence and function of that mode which runs counter to the film\u27s dominant mode of representation (i.e. the home-movie style of Breaking the Waves). What fiction and documentary films that foreground, in a self-reflexive way, the process of their construction illustrate is the fact that all filmic representations are a negotiation between fiction and non-fiction. And it is in that space between fiction and documentary that alternative representations to mainstream, commercial cinema are created
Influence of homology and node-age on the growth of protein-protein interaction networks
Proteins participating in a protein-protein interaction network can be
grouped into homology classes following their common ancestry. Proteins added
to the network correspond to genes added to the classes, so that the dynamics
of the two objects are intrinsically linked. Here, we first introduce a
statistical model describing the joint growth of the network and the
partitioning of nodes into classes, which is studied through a combined
mean-field and simulation approach. We then employ this unified framework to
address the specific issue of the age dependence of protein interactions,
through the definition of three different node wiring/divergence schemes.
Comparison with empirical data indicates that an age-dependent divergence move
is necessary in order to reproduce the basic topological observables together
with the age correlation between interacting nodes visible in empirical data.
We also discuss the possibility of nontrivial joint partition/topology
observables.Comment: 14 pages, 7 figures [accepted for publication in PRE
A Broad Search for Counterrotating Gas and Stars: Evidence for Mergers and Accretion
We measure the frequency of bulk gas-stellar counterrotation in a sample of
67 galaxies drawn from the Nearby Field Galaxy Survey, a broadly representative
survey of the local galaxy population down to M_B-15. We detect 4
counterrotators among 17 E/S0's with extended gas emission (24% +8 -6). In
contrast, we find no clear examples of bulk counterrotation among 38 Sa-Sbc
spirals, although one Sa does show peculiar gas kinematics. This result implies
that, at 95% confidence, no more than 8% of Sa-Sbc spirals are bulk
counterrotators. Among types Sc and later, we identify only one possible
counterrotator, a Magellanic irregular. We use these results together with the
physical properties of the counterrotators to constrain possible origins for
this phenomenon.Comment: 19 pages, 4 figures, AJ, accepte
Planetary Nebulae as standard candles XI. Application to Spiral Galaxies
We report the results of an [O III] lambda 5007 survey for planetary nebulae
(PN) in three spiral galaxies: M101 (NGC 5457), M51 (NGC 5194/5195) and M96
(NGC 3368). By comparing on-band/off-band [O III] lambda 5007 images with
images taken in H-alpha and broadband R, we identify 65, 64 and 74 PN
candidates in each galaxy, respectively. From these data, an adopted M31
distance of 770 kpc, and the empirical planetary nebula luminosity function
(PNLF), we derive distances to M101, M51, and M96 of 7.7 +/- 0.5, 8.4 +/- 0.6,
and 9.6 +/- 0.6 Mpc. These observations demonstrate that the PNLF technique can
be successfully applied to late-type galaxies, and provide an important overlap
between the Population I and Population II distance scales. We also discuss
some special problems associated with using the PNLF in spiral galaxies,
including the effects of dust and the possible presence of [O III] bright
supernova remnants.Comment: 38 pages, TeX, with tables included but not figures. Uses epsf.tex
and kpnobasic.tex. To be published in the Astophysical Journal. Full paper is
available at http://www.astro.psu.edu/users/johnf/Text/research.htm
Extragalactic OH megamasers in strong IRAS sources
From the OH and HI survey of the strongest far infrared IRAS sources, 3 new powerful OH megamasers were discovered in Arp 143, IRAS 1510+0724 and in the uncatalogued IRAS source, IRAS 17208-0014. The HI line, the OH 1667 and 1665 MHz main lines and the 21 cm continuum observations were made with Nancy radio telescope. The optical spectra and images were obtained at the European Southern Observatory. The spectra are displayed in figures together with the main IR and OH properties of the 8 megamasers detected up to now, including IC 4553, NGC 3690 and Mrk 231, Mrk 273 and III ZW35
Clues to Nuclear Star Cluster Formation from Edge-on Spirals
We find 9 nuclear cluster candidates in a sample of 14 edge-on, late-type
galaxies observed with HST/ACS. These clusters have magnitudes (M_I ~ -11) and
sizes (r_eff ~ 3pc) similar to those found in previous studies of face-on,
late-type spirals and dE galaxies. However, three of the nuclear clusters are
significantly flattened and show evidence for multiple, coincident structural
components. The elongations of these three clusters are aligned to within 10
degrees of the galaxies' major axes. Structurally, the flattened clusters are
well fit by a combination of a spheroid and a disk or ring. The nuclear cluster
disks/rings have F606W-F814W (~V-I) colors 0.3-0.6 magnitudes bluer than the
spheroid components, suggesting that the stars in these components have ages <
1 Gyr. In NGC 4244, the nearest of the nuclear clusters, we further constrain
the stellar populations and provide a lower limit on the dynamical mass via
spectroscopy. We also present tentative evidence that another of the nuclear
clusters (in NGC 4206) may also host a supermassive black hole. Based on our
observational results we propose an in situ formation mechanism for nuclear
clusters in which stars form episodically in compact nuclear disks, and then
lose angular momentum or heat vertically to form an older spheroidal structure.
We estimate the period between star formation episodes to be 0.5 Gyr and
discuss possible mechanisms for tranforming the disk-like components into
spheroids. We also note the connection between our objects and massive globular
clusters (e.g. Cen), UCDs, and SMBHs. (Abridged)Comment: Accepted for publication in the A
Cepheid and Tip of the Red Giant Branch Distances To the Dwarf Irregular Galaxy IC10
We present color-magnitude diagrams and luminosity functions of stars in the
nearby galaxy IC 10, based on VI CCD photometry acquired with the COSMIC
prime-focus camera on the Palomar 5m telescope. The apparent I-band luminosity
function of stars in the halo of IC 10 shows an identifiable rise at I~21.7
mag. This is interpreted as being the tip of the red giant branch (TRGB) at
M_V~-4 mag. Since IC 10 is at a very low Galactic latitude, its foreground
extinction is expected to be high and the uncertainty associated with that
correction is the largest contributor to the error associated with its distance
determination. Multi-wavelength observations of Cepheid variable stars in IC 10
give a Population I distance modulus of 24.1 +- 0.2 mag, which corresponds to a
linear distance of 660 +- 66 kpc for a total line-of-sight reddening of E(B-V)
= 1.16 +- 0.08 mag, derived self-consistently from the Cepheid data alone.
Applying this Population I reddening to the Population II halo stars gives a
TRGB distance modulus of 23.5 +- 0.2 mag, corresponding to 500 +- 50 kpc. We
consider this to be a lower limit on the TRGB distance. Reconciling the Cepheid
and TRGB distances would require that the reddening to the halo is
E(B-V) = 0.31 mag lower than that into the main body of the galaxy.
This then suggests that the Galactic extinction in the direction of IC10 is
(B-V) ~ 0.85
An interferometric study of the low-mass protostar IRAS 16293-2422: small scale organic chemistry
Aims: To investigate the chemical relations between complex organics based on
their spatial distributions and excitation conditions in the low-mass young
stellar objects IRAS 16293-2422 A and B. Methods: Interferometric observations
with the Submillimeter Array have been performed at 5''x3'' resolution
revealing emission lines of HNCO, CH3CN, CH2CO, CH3CHO and C2H5OH. Rotational
temperatures are determined from rotational diagrams when a sufficient number
of lines are detected. Results: Compact emission is detected for all species
studied here. For HNCO and CH3CN it mostly arises from source A, CH2CO and
C2H5OH have comparable strength for both sources and CH3CHO arises exclusively
from source B. HNCO, CH3CN and CH3CHO have rotational temperatures >200 K. The
(u,v)-visibility data reveal that HNCO also has extended cold emission.
Conclusions: The abundances of the molecules studied here are very similar
within factors of a few to those found in high-mass YSOs. Thus the chemistry
between high- and low-mass objects appears to be independent of luminosity and
cloud mass. Bigger abundance differences are seen between the A and B source.
The HNCO abundance relative to CH3OH is ~4 times higher toward A, which may be
due to a higher initial OCN- ice abundances in source A compared to B.
Furthermore, not all oxygen-bearing species are co-existent. The different
spatial behavior of CH2CO and C2H5OH compared with CH3CHO suggests that
hydrogenation reactions on grain-surfaces are not sufficient to explain the
observed gas phase abundances. Selective destruction of CH3CHO may result in
the anti-coincidence of these species in source A. These results illustrate the
power of interferometric compared with single dish data in terms of testing
chemical models.Comment: 11 pages, 15 figures, accepeted by A&
Distorted HI Gas in the Widely Separated LIRG Arp 256
We present new interferometric HI and CO (1-0) observations of the luminous
infrared source, Arp 256. Arp 256 consists of two spiral galaxies in an early
stage of merging, with a projected nuclear separation of 29 kpc (54") and an
infrared luminosity of 2.0E11 L_sun. Despite the large separation of the
galaxies' nuclei and mildly disrupted stellar components, the HI disks are
found to be strongly disrupted, and the southern galaxy in Arp 256 shows an
elevated star formation efficiency, which is consistent with a nuclear
starburst. Both of these results run contrary to expectations, posing
interesting questions on the physical mechanisms involved in stimulating star
formation during an interaction.Comment: 19 pages, 7 figures. Accepted for publication in AJ. Author added.
Full resolution figures available at
http://astro.uchicago.edu/home/web/jchen/arp25
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