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Supernovae 2005ds, 2005em, 2005er, 2005es, 2005et, 2005eu
IAUC 8611 available at Central Bureau for Astronomical Telegrams.
| Properties of Molecular Gas in Massive Low Surface Brightness Galaxies, Including New 12CO Observations of Three Malin 1 ``Cousins''
To date, the only low surface brightness (LSB) galaxies that have beendetected in CO are the massive LSB (MLSB) galaxies. In 2003, O'Neil,Schinnerer, & Hofner hypothesized that it is the prominent bulgecomponent in MLSB galaxies, not present in less massive LSB galaxies,that gives rise to the detectable quantities of CO gas. To test thishypothesis, we have used the IRAM 30 m telescope to obtain three new,deep CO J(1-0) and J(2-1) observations of MLSB galaxies. Two of thethree galaxies observed were detected in CO-one in the J(1-0) line andthe other in both the J(1-0) and J(2-1) lines-bringing the total numberof MLSB galaxies with CO detections to five, out of a total of nine MLSBgalaxies observed at CO to date. The third object had no detection to 2mK at CO J(1-0). Comparing all MLSB galaxy CO results with surveys ofhigh surface brightness galaxies, we find that the MLSB galaxies'MH2 and MH2/MHIvalues fall within the ranges typically found for high surfacebrightness objects, albeit at the low end of the distribution, with thetwo MLSB galaxies detected at CO in this survey having the highestMH2/MHI values yet measured for any LSBsystem, by factors of 2-3.
| The First CO Map of a Low Surface Brightness Galaxy
Using the Owens Valley Radio Observatory (OVRO) Millimeter-WavelengthArray, we have obtained the first CO map of a low surface brightness(LSB) galaxy. The studied galaxy, UGC 01922, was chosen for theseobservations because of both its previous CO detection with the IRAM 30m telescope and its classification as a Malin 1 ``cousin'' an LSB galaxywith MHI>=1010 Msolar. The OVRO mapdetected approximately 65% of the CO (1-0) flux found earlier with thesingle-dish measurements, giving a detected gas mass equivalent toMH2=1.1×109 Msolar.The integrated gas peak lies at the center of the galaxy and coincideswith both the optical and 1.4 GHz continuum emission peaks. Themolecular gas extends well beyond the OVRO beam size (~4" or 3 kpc),covering ~25% of the optical bulge. In all, perhaps the most remarkableaspect of this map is its unexceptional appearance. Given that it tookover 10 years to successfully detect molecular gas in any LSB system, itis surprising that the appearance and distribution of UGC 01922's CO issimilar to what would be expected for a high surface brightness galaxyin the same morphological class.
| Further Discoveries of 12CO in Low Surface Brightness Galaxies
Using the IRAM 30 m telescope we have obtained seven new, deep CO J(1-0)and J(2-1) observations of low surface brightness (LSB) galaxies. Fiveof the galaxies have no CO detected to extremely low limits [0.1-0.4 Kkm s-1 at J(1-0)], while two of the galaxies, UGC 01922 andUGC 12289, have clear detections in both line transitions. When theseobservations are combined with all previous CO observations taken of LSBsystems, we compile a total of 34 observations, in which only threegalaxies have had detections of their molecular gas. Comparing the LSBgalaxies with and without CO detections with a sample of high surfacebrightness (HSB) galaxies with CO observations indicates that it isprimarily the low density of baryonic matter within LSB galaxies that iscausing their low CO fluxes. Finally, we note that one of the massiveLSB galaxies studied in this project, UGC 06968 (a Malin 1 ``cousin''),has upper limits placed on both MH2 andMH2/MHI that are 10-20 times lower thanthe lowest values found for any galaxy (LSB or HSB) with similar globalproperties. This may be due to an extremely low temperature andmetallicity within UGC 06968 or simply due to the CO distribution withinthe galaxy being too diffuse to be detected by the IRAM beam.
| Arcsecond Positions of UGC Galaxies
We present accurate B1950 and J2000 positions for all confirmed galaxiesin the Uppsala General Catalog (UGC). The positions were measuredvisually from Digitized Sky Survey images with rms uncertaintiesσ<=[(1.2")2+(θ/100)2]1/2,where θ is the major-axis diameter. We compared each galaxymeasured with the original UGC description to ensure high reliability.The full position list is available in the electronic version only.
| Extensive Spiral Structure and Corotation Resonance
Spiral density wave theories demand that grand-design spiral structurebe bounded, at most, between the inner and outer Lindblad resonances ofthe spiral pattern. The corotation resonance lies between the outer andthe inner Lindblad resonances. The locations of the resonances are atradii whose ratios to each other are rather independent of the shape ofthe rotation curve. The measured ratio of outer to inner extent ofspiral structure for a given spiral galaxy can be compared to thestandard ratio of corotation to inner Lindblad resonance radius. In thecase that the measured ratio far exceeds the standard ratio, it islikely that the corotation resonance is within the bright optical disk.Studying such galaxies can teach us how the action of resonances sculptsthe appearance of spiral disks. This paper reports observations of 140disk galaxies, leading to resonance ratio tests for 109 qualified spiralgalaxies. It lists candidates that have a good chance of having thecorotation resonance radius within the bright optical disk.
| Active Galactic Nucleus Activity in Giant, Low Surface Brightness Galaxies
A search of large, H i-rich disk galaxies finds a significantly higherfraction of low-luminosity active galactic nucleus (AGN) signaturescompared with other late-type galaxies. Approximately half the galaxiesselected in this sample have AGN-like behavior in their cores; the resthave H ii nuclei resulting from simple star formation. Since AGNbehavior is not evident in all the sample galaxies, which where selectedby high gas mass, we speculate that it is the fuel flow rate that is thecommon feature between late-type low surface brightness disks and otheractive nuclear galaxies.
| An image database. II. Catalogue between δ=-30deg and δ=70deg.
A preliminary list of 68.040 galaxies was built from extraction of35.841 digitized images of the Palomar Sky Survey (Paper I). For eachgalaxy, the basic parameters are obtained: coordinates, diameter, axisratio, total magnitude, position angle. On this preliminary list, weapply severe selection rules to get a catalog of 28.000 galaxies, wellidentified and well documented. For each parameter, a comparison is madewith standard measurements. The accuracy of the raw photometricparameters is quite good despite of the simplicity of the method.Without any local correction, the standard error on the total magnitudeis about 0.5 magnitude up to a total magnitude of B_T_=17. Significantsecondary effects are detected concerning the magnitudes: distance toplate center effect and air-mass effect.
| A catalog of recent supernovae
A listing is given of all supernovae discovered between 1 Jan 1989 and 1Apr 1993. The data show no evidence for a significant dependence of thediscovery probability of supernovae on parent galaxy inclination to theline of sight. If no inclination corrections need to be applied then thesupernova rates in spirals are only about half as large as previouslybelieved. The mean linear separation of supernovae of Type II (SNe II)from the center of their parent galaxy increases with increasingdistance (Shaw effect). The Shaw effect appears less evident, or absent,for (more luminous) supernovae of Type Ia. The data are consistent with,but do not prove, the hypothesis that (presumably reddended) SNe II aremore likely to be discovered in the red than in the blue. Due tointensive surveillance, most bright SNe Ia tend to be found beforemaximum, whereas the majority of faint SNe Ia are discovered aftermaximum light.
| Supernova 1989S in IC 226
IAUC 4888 available at Central Bureau for Astronomical Telegrams.IAUC 4888 available at Central Bureau for Astronomical Telegrams.
| A 21 CM survey of the Pisces-Perseus supercluster. I - The declination zone +27.5 to +33.5 degrees
Neutral-hydrogen 21 cm line data for a sample of galaxies in the regionbounded by 22 h less than R.A. less than 04h, + 27 deg 30 arcmin Dec.less than + 33 deg 30 arcmin are presented as the first installment of asurvey of galaxies in the region of the Pisces-Perseus supercluster. Ofthe 415 galaxies observed in this strip with the Arecibo 305 mtelescope, 342 have been detached in the 21 cm line; another ten haveuseful upper limits to their H I content. The sample includes mostspiral, irregular, and dwarf galaxies larger than 1 arcmin; in selectedareas, spirals to a limiting magnitude of + 15.7 have been observed. Thevelocity distribution of the 511 galaxies with known redshift in thiszone deviates markedly from that expected for a similar sample ofrandomly placed objects. The region contains significant clustering inall three dimensions.
| Neutral hydrogen in isolated galaxies. IV - Results for the Arecibo sample
A standard sample for the comparison of the H I content of galaxies invarious intergalactic environments is presently defined by means ofobservations of 324 isolated galaxies lying in the declination rangeaccessible to the Arecibo 305-m telescope. Both mapping and single pointspectra are used to compute the integral properties of these galaxies.Neutral hydrogen was detected in 288 of the 324 galaxies surveyed, andit is noted that the optical diameter of a spiral disk is bettercorrelated with the hydrogen mass than the morphological type. When usedto define a measure of H I content, the isolated galaxy sample canpredict 'normalcy' with an accuracy that carries a standard error ofabout 0.20 in the log of the H I mass, if a dependence on disk size, aswell as type, is taken into account.
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