SDSS J122958.84+000138.0: A Compact, Optically red galaxy

We report a new compact galaxy, SDSS J122958.84+000138.0 (SDSS J1229+0001), which has unique morphological and stellar population properties that are rare in observations of the nearby universe. SDSS J1229+0001 has an $r$-band absolute magnitude (M$_{r}$) and half-light radius (R$_{h}$) of $-$17.75 mag and 520 pc, respectively. Located in a fairly low density environment, morphologically it is akin to a typical early-type galaxy as it has a smooth appearance and red colour. But, interestingly, it possesses centrally concentrated star forming activity with a significant amount of dust. We present an analysis of structural and stellar population properties using archival images and VLT/FORS2 spectroscopy. Analysis of UKIDSS H-band image shows that the observed light distribution is better fitted with two components S\'ersic function with inner and outer component effective radii 190 and 330 pc, respectively. Whereas, overall half-light radius measured in H-band is much smaller compared to optical, i.e 290 pc. We prepared a Spectral Energy Distribution (SED) from optical to FIR and interpret it to derive star-formation rate, dust mass and stellar mass. We find that the SDSS J1229+0001 has dust mass M$_{dust}$ = 5.1 $\times$ 10$^{5}$ M_{\sun} with a dust to stellar mass ratio log(M$_{dust}$/M$_{*}$) = $-$3.5. While the observed stellar population properties are -- to some extent -- similar to that of a typical S0 galaxy, a unified view from stellar population and structural properties may suggests that SDSS J1229+0001 is a {\it smoking gun} example of a compact early-type galaxy in formation.Comment: 10 pages, Accepted MNRA

Structural characterization of the Fddd phase in a diblock copolymer thin film by electron microtomography

A 3-dimensional Fddd network structure of a polystyrene-block-polyisoprene (PS-b-PI) diblock copolymer (M(n) = 31 500, f(PI) = 0.645) was observed for the first time in real space by transmission electron microtomography (TEMT). In a 650 nm thick film of the PS-b-PI thin film on a silicon wafer, the Fddd phase was developed after annealing at 215 degrees C for 24 h. The single network structure consists of the connected tripodal units of minor PS block domains. The {111}(Fddd) plane, the densest plane of the minor PS phase, was found to orient parallel to the film plane. The transitional structure from the wetting layer at the free surface to the internal {111}(Fddd) plane via a perforated layer structure was also observed.X111313sciescopu

Scattering properties of a cut-circle billiard waveguide with two conical leads

We examine a two-dimensional electron waveguide with a cut-circle cavity and conical leads. By considering Wigner delay times and the Landauer-B\"{u}ttiker conductance for this system, we probe the effects of the closed billiard energy spectrum on scattering properties in the limit of weakly coupled leads. We investigate how lead placement and cavity shape affect these conductance and time delay spectra of the waveguide.Comment: 18 pages, 11 figures, accepted for publication in Phys. Rev. E (Jan. 2001

Post-merger Signatures of Red-sequence Galaxies in Rich Abell Clusters at z≲0.1z\lesssim 0.1

We have investigated the post-merger signatures of red-sequence galaxies in rich Abell clusters at $z \lesssim$ 0.1: A119, A2670, A3330 and A389. Deep images in u', g', r' and medium-resolution galaxy spectra were taken using MOSAIC 2 CCD and Hydra MOS mounted on a Blanco 4-m telescope at CTIO. Post-merger features are identified by visual inspection based on asymmetric disturbed features, faint structures, discontinuous halo structures, rings and dust lanes. We found that ~ 25% of bright (M_r < -20) cluster red-sequence galaxies show post-merger signatures in four clusters consistently. Most (~ 71%) of the featured galaxies were found to be bulge-dominated, and for the subsample of bulge-dominated red-sequence galaxies, the post-merger fraction rises to ~ 38%. We also found that roughly 4% of bulge-dominated red-sequence galaxies interact (on-going merger). A total of 42% (38% post-merger, 4% on-going merger) of galaxies show merger-related features. Compared to a field galaxy study with a similar limiting magnitude (van Dokkum 2005), our cluster study presents a similar post-merger fraction but a markedly lower on-going merger fraction. The merger fraction derived is surprisingly high for the high density of our clusters, where the fast internal motions of galaxies are thought to play a negative role in galaxy mergers. The fraction of post-merger and on-going merger galaxies can be explained as follows. Most of the post-merger galaxies may have carried over their merger features from their previous halo environment, whereas interacting galaxies interact in the current cluster in situ. According to our semi-analytic calculation, massive cluster haloes may very well have experienced tens of halo mergers over the last 4-5 Gyr; post-merger features last that long, allowing these features to be detected in our clusters today. (Abridged)Comment: 16 pages, 15 figures, 7 tables, accepted for publication in ApJ