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Articles 1 - 8 of 8
Full-Text Articles in Physical Sciences and Mathematics
Luminosity Profiles Of Merger Remnants, J E. Hibbard, Min S. Yun
Luminosity Profiles Of Merger Remnants, J E. Hibbard, Min S. Yun
Min S. Yun
Using published luminosity and molecular gas profiles of the late-stage mergers NGC 3921, NGC 7252, and Arp 220, we examine the expected luminosity profiles of the evolved merger remnants, especially in light of the massive CO complexes that are observed in their nuclei. For NGC 3921 and NGC 7252, we predict that the resulting luminosity profiles will be characterized by an r1/4 law. In view of previous optical work on these systems, it seems likely that they will evolve into normal elliptical galaxies as regards their optical properties. Due to a much higher central molecular gas column density, Arp 220 …
Detection Of Co (2-1) And Radio Continuum Emission From The Z = 4.4 Qso Bri 1335–0417, C L. Carilli, Karl M. Menten, Min S. Yun
Detection Of Co (2-1) And Radio Continuum Emission From The Z = 4.4 Qso Bri 1335–0417, C L. Carilli, Karl M. Menten, Min S. Yun
Min S. Yun
We have detected redshifted CO (2-1) emission at 43 GHz and radio continuum emission at 1.47 and 4.86 GHz from the z = 4.4 QSO BRI 1335-0417 using the Very Large Array. The CO data imply optically thick emission from warm (>30 K) molecular gas with a total mass, M(H2), of (1.5 ± 0.3) × 1011 Msun, using the standard Galactic gas mass-to-CO luminosity conversion factor. We set an upper limit to the CO source size of 1farcs1 and a lower limit of 0farcs23(Tex/50 K)-1/2, where Tex is the gas excitation temperature. We derive an upper limit to the …
Molecular Gas In The Z = 2.565 Submillimeter Galaxy Smm J14011+0252, D T. Frayer, R J. Ivison, N Z. Scoville, A S. Evans, Min S. Yun, Ian Smail, A J. Barger, A W. Blain, J P. Kneib
Molecular Gas In The Z = 2.565 Submillimeter Galaxy Smm J14011+0252, D T. Frayer, R J. Ivison, N Z. Scoville, A S. Evans, Min S. Yun, Ian Smail, A J. Barger, A W. Blain, J P. Kneib
Min S. Yun
We report the detection of CO (3 r 2) emission from the submillimeter-selected luminous galaxy SMM J1401110252. The optical counterpart of the submillimeter source has been identified as a merger system with spectral characteristics consistent with a starburst at z 5 2.565. The CO emission confirms the optical identification of the submillimeter source and implies a molecular gas mass of M,5#1010 h22 , after correcting 75 for a lensing amplification factor of 2.75. The large molecular gas mass and the radio emission are consistent with the starburst interpretation of the source. These results are similar to those found for SMM …
The Peculiar Motions Of Early-Type Galaxies In Two Distant Regions -- V. The Mg-- Relation, Age And Metallicity, M. Colless, D. Burstein, R. L. Davies, R. K. Mcmahan, R. P. Saglia, G. Wegner
The Peculiar Motions Of Early-Type Galaxies In Two Distant Regions -- V. The Mg-- Relation, Age And Metallicity, M. Colless, D. Burstein, R. L. Davies, R. K. Mcmahan, R. P. Saglia, G. Wegner
Dartmouth Scholarship
We have examined the Mg—σ relation for early-type galaxies in the EFAR sample and its dependence on cluster properties. A comprehensive maximum likelihood treatment of the sample selection and measurement errors gives fits to the global Mg—σ relation of Mg b′=0.131 log σ −0.131 and Mg2=0.257 log σ −0.305. The slope of these relations is 25 per cent steeper than that obtained by most other authors owing to the reduced bias of our fitting method. The intrinsic scatter in the global Mg— σ relation is estimated to be 0.016 mag in Mg b′ and 0.023 …
The Radio-To-Submillimeter Spectral Index As A Redshift Indicator, C L. Carilli, Min S. Yun
The Radio-To-Submillimeter Spectral Index As A Redshift Indicator, C L. Carilli, Min S. Yun
Min S. Yun
We present models of the 1.4 to 350 GHz spectral index 350 for starburst galaxies as a function of redshift. a1.4 The models include a semianalytic formulation, based on the well-quantified radio–to–far-infrared correlation for low-redshift star-forming galaxies, and an empirical formulation, based on the observed spectrum of the starburst galaxies M82 and Arp 220. We compare the models to the observed values of 350 for starburst galaxies at low a1.4 and high redshift. We find reasonable agreement between the models and the observations and, in particular, that an observed spectral index of 350 indicates that the target source is likely …
Co Distribution And Kinematics Along The Bar In The Strongly Barred Spiral Ngc 7479, S Laine, J D P Kenny, Min S. Yun, S T. Gottesman
Co Distribution And Kinematics Along The Bar In The Strongly Barred Spiral Ngc 7479, S Laine, J D P Kenny, Min S. Yun, S T. Gottesman
Min S. Yun
We report on the 2farcs5 (400 pc) resolution CO (J=1→0) observations covering the whole length of the bar in the strongly barred late-type spiral galaxy NGC 7479. CO emission is detected only along a dust lane that traverses the whole length of the bar, including the nucleus. The emission is strongest in the nucleus. The distribution of emission is clumpy along the bar outside the nucleus and consists of gas complexes that are unlikely to be gravitationally bound. The CO kinematics within the bar consist of two separate components. A kinematically distinct circumnuclear disk, <500 pc in diameter, is undergoing predominantly circular motion with a maximum rotational velocity of 245 km s-1 at a radius of 1'' (160 pc). The CO-emitting gas in the bar outside the circumnuclear disk has substantial noncircular motions that are consistent with a large radial velocity component, directed inward. The CO emission has a large velocity gradient across the bar dust lane, ranging from 0.5 to 1.9 km s-1 pc-1 after correcting for inclination, and the projected velocity change across the dust lane is as high as 200 km s-1. This sharp velocity gradient is consistent with a shock front at the location of the bar dust lane. A comparison of Hα and CO kinematics across the dust lane shows that, although the Hα emission is often observed both upstream and downstream from the dust lane, the CO emission is observed only where the velocity gradient is large. We also compare the observations with hydrodynamic models and discuss star formation along the bar.
Submillimeter Imaging Of The Luminous Infrared Galaxy Pair Vv 114, D T. Frayer, R J. Ivison, I Smail, L Armus, Min S. Yun
Submillimeter Imaging Of The Luminous Infrared Galaxy Pair Vv 114, D T. Frayer, R J. Ivison, I Smail, L Armus, Min S. Yun
Min S. Yun
We report on 450 and 850 μm observations of the interacting galaxy pair VV 114 E+W (IC 1623), taken with the SCUBA camera on the James Clerk Maxwell Telescope, and near-infrared observations taken with the UKIRT Fast-Track Imager on the UK Infrared Telescope. The system VV 114 is in an early stage of a gas-rich merger. We detect submillimeter emission extended over 30'' (12 kpc) and find a good correlation between the spatial distribution of the submillimeter and CO emission. Both the CO and submillimeter emission peak near the reddest region of VV 114 E and extend toward VV 114 …
Counterrotating Nuclear Disks In Arp 220, K Sakamoto, N Z. Scoville, Min S. Yun, M Crosas, R Genzel, L J. Tacconi
Counterrotating Nuclear Disks In Arp 220, K Sakamoto, N Z. Scoville, Min S. Yun, M Crosas, R Genzel, L J. Tacconi
Min S. Yun
The ultraluminous infrared galaxy Arp 220 has been observed at 0farcs5 resolution in CO (2-1) and 1 mm continuum using the newly expanded Owens Valley Millimeter Array. The CO and continuum peaks at the double nuclei and the surrounding molecular gas disk are clearly resolved. We find steep velocity gradients across each nucleus (ΔV~500 km s-1 within r=0farcs3) whose directions are not aligned with each other and with that of the outer gas disk. We conclude that the double nuclei have their own gas disks (r~100 pc), are counterrotating with respect to each other, and are embedded in the outer …