scholarly journals The Distribution of [O [CSC]ii[/CSC]] Emission-Line Widths of Las Campanas Redshift Survey Galaxies

2000 ◽  
Vol 543 (2) ◽  
pp. L125-L128 ◽  
Author(s):  
Michael Blanton ◽  
Huan Lin
2007 ◽  
Vol 3 (S245) ◽  
pp. 233-234
Author(s):  
A. Beifiori ◽  
E. M. Corsini ◽  
E. Dalla Bontà ◽  
A. Pizzella ◽  
L. Coccato ◽  
...  

AbstractThe growth of supermassive black holes (SMBHs) appears to be closely linked with the formation of spheroids. There is a pressing need to acquire better statistics on SMBH masses, since the existing samples are preferentially weighted toward early-type galaxies with very massive SMBHs. With this motivation we started a project aimed at measuring upper limits on the mass of the SMBHs that can be present in the center of all the nearby galaxies (D < 100 Mpc) for which STIS/G750M spectra are available in the HST archive. These upper limits will be derived by modeling the central emission-line widths ([N II] λλ6548, 6583, Hα and [S II] λλ6716, 6731) observed over an aperture of ~01 (R < 50 pc). Here we present our preliminary results for a subsample of 76 bulges.


Solar Physics ◽  
1971 ◽  
Vol 17 (2) ◽  
pp. 316-330 ◽  
Author(s):  
M. K. V. Bappu ◽  
K. R. Sivaraman

2020 ◽  
Vol 56 (45) ◽  
pp. 6130-6133 ◽  
Author(s):  
Xiao Jin ◽  
Kanlin Xie ◽  
Tingting Zhang ◽  
Huada Lian ◽  
Zhenghe Zhang ◽  
...  

ZnCdSe/ZnSe quantum dots reveal a notable FWHM of 17.1 nm with a near-unity PL QY at 631 nm.


2018 ◽  
Vol 620 ◽  
pp. A193 ◽  
Author(s):  
D. Vergani ◽  
B. Garilli ◽  
M. Polletta ◽  
P. Franzetti ◽  
M. Scodeggio ◽  
...  

Aims. We analyse the properties of the host galaxies of a [NeV]-selected sample to investigate whether and how they are affected by the AGN. Methods. We have selected a sample of galaxies at 0.62 <  z <  1.2 from the VIMOS Public Extragalactic Redshift Survey (VIPERS) and divided it in blue cloud galaxies, red passive galaxies and green valley galaxies using the NUVrK diagram. Within each category, galaxies with AGN activity were identified based on the detection of the high-ionisation [NeV]λ3426 emission line. For each galaxy we derived several properties (stellar age and mass, the (r−K) colour, the [OII] luminosity) and compared them between active and inactive galaxies matched in stellar mass and redshift. Results. We find statistically significant differences in the properties between active and inactive galaxies. These differences imply that the AGN is more often found in galaxies with younger stellar populations and more recent star-forming activity than their parent samples. Interestingly, the AGN identified through the [NeV]λ3426 emission line is not commonly found by traditional AGN-selection techniques based on shallow X-ray data, mid-IR colours, and classical line diagnostic diagrams, and might thus reveal a specific evolutionary phase. The spectral analysis reveals a sub-set of AGN within the blue cloud that has spectral signatures implying a sudden suppression of star formation activity similar to post-starburst galaxies. Conclusion. Using the rich dataset of the large VIPERS sample we identify a novel class of active post-starburst galaxies that would be missed by traditional selection techniques. These galaxies belong to the blue cloud, but their star-formation activity has been recently suppressed, possibly by the AGN identified through the presence of the [NeV]λ3426 emission line in their spectra. Our results support the idea that AGN feedback may be responsible for halting star-formation in active blue galaxies and for their transition into the red sequence, at least in the 0.6–1.2 redshift range and for stellar masses greater than 5 × 1010 ℳ⊙. Our results are based on a complete spectroscopic sample and limited by the [NeV] observability, and the AGN can be variable and with a relatively short duty cycle. Considering this, AGN feedback that makes blue galaxies quickly transition to the red sequence may be even more common than previously believed.


Author(s):  
Motonari Tonegawa ◽  
Teppei Okumura ◽  
Tomonori Totani ◽  
Gavin Dalton ◽  
Karl Glazebrook ◽  
...  

2020 ◽  
Vol 499 (3) ◽  
pp. 3943-3960 ◽  
Author(s):  
Hui Kong ◽  
Kaylan J Burleigh ◽  
Ashley Ross ◽  
John Moustakas ◽  
Chia-Hsun Chuang ◽  
...  

ABSTRACT This work presents the application of a new tool, Obiwan, which uses image simulations to determine the selection function of a galaxy redshift survey and calculate three-dimensional (3D) clustering statistics. Obiwan relies on a forward model of the process by which images of the night sky are transformed into a 3D large-scale structure catalogue, and offers several advantages over more traditional map-based techniques – such as operating on individual exposures and adopting a maximum likelihood approach. The photometric pipeline automatically detects and models galaxies and then generates a catalogue of such galaxies with detailed information for each one of them, including their location, redshift, and so on. Systematic biases in the imaging data are therefore imparted into the catalogues and must be accounted for in any scientific analysis of their information content. Obiwan simulates this process for samples selected from the Legacy Surveys imaging data. This imaging data will be used to select target samples for the next-generation Dark Energy Spectroscopic Instrument (DESI) experiment. Here, we apply Obiwan to a portion of the SDSS-IV extended Baryon Oscillation Spectroscopic Survey emission-line galaxies (ELGs). Systematic biases in the data are clearly identified and removed. We compare the 3D clustering results to those obtained by the map-based approach applied to the complete eBOSS Data Release 16 (DR16) sample. We find the results are consistent, thereby validating the eBOSS DR16 ELG catalogues, which is used to obtain cosmological results.


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