Search Publications
Spectral analysis of the hybrid PG 1159-type central stars of the planetary nebulae Abell 43 and NGC 7094
Rauch, T.; Werner, K.; Kruk, J. W. +5 more
Stellar post asymptotic giant branch (post-AGB) evolution can be completely altered by a final thermal pulse (FTP) which may occur when the star is still leaving the AGB (AFTP), at the departure from the AGB at still constant luminosity (late TP, LTP) or after the entry to the white-dwarf cooling sequence (very late TP, VLTP). Then convection mixe…
RCW 120: a possible case of hit and run, elucidated by multitemperature dust mapping
Marsh, K. A.; Whitworth, A. P.
We present resolution-enhanced images of warm dust at multiple temperatures and opacity index values in the star-forming bubble/H II region, RCW 120. The image set, representing a four-dimensional hypercube of differential column density, was obtained using our Bayesian procedure, PPMAP. The cool peripheral material (∼16-22 K) exhibits ragged clum…
Chemical abundances of open clusters from high-resolution infrared spectra - I. NGC 6940
Sneden, C.; Pilachowski, C. A.; Mace, G. N. +8 more
We present near-infrared spectroscopic analysis of 12 red giant members of the Galactic open cluster NGC 6940. High-resolution (R ≃ 45 000) and high-signal-to-noise ratio (S/N > 100) near-infrared H- and K-band spectra were gathered with the Immersion Grating Infrared Spectrograph (IGRINS) on the 2.7-m Smith Telescope at McDonald Observatory. W…
Graphene oxide nanoparticles in the interstellar medium
Sarre, P. J.
Dust particles play a major role in the formation, evolution and chemistry of interstellar clouds, stars, and planetary systems. Commonly identified forms include amorphous and crystalline carbon-rich particles and silicates. Also present in many astrophysical environments are polycyclic aromatic hydrocarbons (PAHs), detected through their infrare…
Compact star-forming galaxies preferentially quenched to become PSBs in z < 1 clusters
Simpson, Chris; Wild, Vivienne; Almaini, Omar +5 more
We analyse the structure of galaxies with high specific star formation rate (SSFR) in cluster and field environments in the redshift range 0.5 < z < 1.0. Recent studies have shown that these galaxies are strongly depleted in dense environments due to rapid environmental quenching, giving rise to post-starburst galaxies (PSBs). We use effecti…
Discovery statistics and 1/a distribution of long-period comets detected during 1801-2017
Dybczyński, Piotr A.; Królikowska, Małgorzata
For the last two decades, we have been observing a huge increase in discoveries of long-period comets (LPCs), especially those with large perihelion distances. We collected data for a full sample of LPCs discovered during 1801-2017, including their osculating orbits, discovery moments (to study the discovery distances) and original semimajor axes …
New luminous blue variable candidates in NGC 4736
Vinokurov, A.; Solovyeva, Y.; Atapin, K. +8 more
We have found three new luminous blue variable (LBV) candidates in the star-forming galaxy NGC 4736. They show typical well-known LBV spectra, broad and strong hydrogen lines, He I lines, many Fe II lines, and forbidden [Fe II] and [Fe III]. Using archival Hubble Space Telescope and ground-based telescope data, we have estimated the bolometric mag…
Star formation in far-IR AGN and non-AGN galaxies in the green valley - II. Morphological analysis
Pović, Mirjana; Väisänen, Petri; Mahoro, Antoine +2 more
This paper studies morphological properties of 103 green valley FIR active and 2609 non-active galaxies presented in Mahoro, Pović & Nkundabakura (2017). The photometric data from the COSMOS survey were used, and the morphological parameters, such as Abraham and Conselice-Bershady concentration indices, Gini, M20 moment of light, and asymmetry…
Chemical analysis of K giants in the young open cluster NGC 2345
Pereira, C. B.; Holanda, N.; Drake, N. A.
We present results for the elemental abundances of five K giants of the young open cluster NGC 2345. The atmospheric parameters of the studied giants and their chemical abundances were determined using high-resolution optical spectroscopy. In this study, we determine abundances of light elements (Li, C, N), light odd-Z elements (Na, Al), α-element…
Detailed study of the Milky Way globular cluster Laevens 3
Martin, Nicolas; Ibata, Rodrigo A.; Mackey, Dougal +4 more
We present a photometric and spectroscopic study of the Milky Way satellite Laevens 3. Using MegaCam/Canada-France-Hawaii Telescope g and i photometry and Keck II/DEIMOS multi-object spectroscopy, we refine the structural and stellar properties of the system. The Laevens 3 colour-magnitude diagram shows that it is quite metal-poor, old (13.0 ± 1.0…