An Optical, Near-Infrared, and Kinematic Study of Four Early-Type Resonance Ring Galaxies

1998 ◽  
Vol 116 (3) ◽  
pp. 1142-1162 ◽  
Author(s):  
R. Buta ◽  
Adina J. Alpert ◽  
Melinda Lewis Cobb ◽  
D. A. Crocker ◽  
Guy B. Purcell
Keyword(s):  
Near Infrared ◽  
Early Type ◽  
Kinematic Study ◽  
Ring Galaxies

Erratum: “An Optical, Near-Infrared, and Kinematic Study of Four Early-Type Resonance Ring Galaxies” [Astron. J. [BF]116[/BF], 1142 (1998)]

2000 ◽  
Vol 120 (1) ◽  
pp. 506-506
Author(s):  
R. Buta ◽  
Adina J. Alpert ◽  
Melinda Lewis Cobb ◽  
D. A. Crocker ◽  
Guy B. Purcell
Keyword(s):  
Near Infrared ◽  
Early Type ◽  
Kinematic Study ◽  
Ring Galaxies

scholarly journals Extragalactic GCs in the near-infrared: genuinely old in E/S0's?

2009 ◽  
Vol 5 (S262) ◽  
pp. 315-316
Author(s):  
Ana L. Chies-Santos ◽  
Søren S. Larsen
Keyword(s):  
Globular Cluster ◽  
Stellar Population ◽  
Near Infrared ◽  
Local Group ◽  
Stellar Populations ◽  
Age Dating ◽  
Early Type ◽  
Optical Photometry ◽  
Star Forming ◽  
Optical Images

Globular cluster (GC) systems are powerful probes to study the evolutionary histories of galaxies, being tracers of major star fomation episodes (Brodie & Strader 2006). They are found around all major galaxies and are easy to see far beyond the local group. Age dating GCs therefore helps pinpoint epochs of major star forming events. Spectroscopic age dating though (Strader et al. 2005) is extremely time consuming and can only access the few brightest clusters. An alternative is to combine near-infrared (NIR) and optical photometry, and therefore have a better chance in lifting the age metallicity degeneracy than with optical colours alone. This approach relies in testing GC colours against simple stellar population (SSP) models. The first studies following this technique showed the possible existence of a high percentage of intermediate age (2-3 Gyrs) GCs in early-type galaxies known to contain old stellar populations from integrated light studies. Two strong cases can be listed: NGC 4365 (Puzia et al. 2002, Larsen et al. 2005) and NGC 5846 (Hempel et al. 2003). In the present study we combine NIR deep photometry obtained with the WHT/LIRIS instrument and archival HST/ACS optical images to determine g(F475W), z(F840LP) and K(2.2m) magnitudes and colours of GCs in 14 early-type galaxies.

scholarly journals Early-type galaxies in the near-infrared: 1.5–2.4 $\mu{\rm m}$ spectroscopy

2009 ◽  
Vol 497 (1) ◽  
pp. 41-51 ◽  
Author(s):  
M. Cesetti ◽  
V. D. Ivanov ◽  
L. Morelli ◽  
A. Pizzella ◽  
L. Buson ◽  
...  
Keyword(s):  
Near Infrared ◽  
Early Type

scholarly journals A Comparison of Near Infrared Spectra of the Galactic Center He I Emission Line Sources and Early Type Mass Losing Stars

1996 ◽  
Vol 169 ◽  
pp. 225-230
Author(s):  
R. D. Blum ◽  
D. L. Depoy ◽  
K. Sellgren
Keyword(s):  
Emission Line ◽  
Infrared Spectra ◽  
Near Infrared ◽  
Galactic Center ◽  
Early Type ◽  
Near Infrared Spectra ◽  
Wide Range ◽  
Comparison Stars ◽  
Band Spectra ◽  
Type Mass

We have obtained R ≈ 570 resolution K band spectra of eight sources in the Galactic Center, including four sources within the IRS 16 cluster, IRS 13, IRS 1W, and the compact He I emission line sources AF (also known as AHH) and AHH NW. We have also obtained R ≈ 570 H and K band spectra of nine galactic and LMC early–type mass–losing stars, including Ofpe/WN9 and WN stars. The spectra of both the Galactic Center sources and the comparison stars show a wide range of behavior in the He I (1.70 μm, 2.06 μm, 2.11 μm) and H I (Brackett series) lines. We find significantly larger He I equivalent widths in the AF source and two galactic early type mass losing stars than in any of the LMC stars. Several of the Galactic Center He I sources are found to have higher He I velocity widths than any of the galactic or LMC early type mass losing stars. At least one source, IRS 13, shows a strong red wing to the He I 2.06 μm emission.

scholarly journals Morphology of z ~ 1 galaxies from deep K-band AO imaging

2006 ◽  
Vol 2 (S235) ◽  
pp. 405-405
Author(s):  
Marc Huertas-Company ◽  
Daniel Rouan ◽  
Geneviève Soucail ◽  
Olivier Le Fèvre ◽  
Lidia Tasca
Keyword(s):  
Adaptive Optics ◽  
Spatial Resolution ◽  
Near Infrared ◽  
High Spatial Resolution ◽  
Integration Time ◽  
Early Type ◽  
Distant Galaxies ◽  
First Time ◽  
Concentration Asymmetry ◽  
Adaptive Optics System

AbstractWe present the results of observations of distant galaxies (z ~ 0.8) at high spatial resolution (~0.1"). We observed 7 fields of 1' × 1' with the NACO Adaptive Optics system (VLT) in Ks (2.2μm) band with typical V ~ 14 guide stars and 3h integration time per field. Observed fields are selected within the COSMOS survey area. We analyze the morphologies by means of B/D (Bulge/Disk) decomposition with GIM2D and CAS (Concentration-Asymmetry) estimators for 79 galaxies with magnitudes between Ks = 17 − 23 and classify them in three main morphological types (Late Type, Early Type and Irregulars). We obtain for the first time an estimate of the distribution of galaxy types at redshift z ~ 1 as measured from the near infrared at high spatial resolution.

scholarly journals Euclid preparation

2019 ◽  
Vol 631 ◽  
pp. A85 ◽  
Author(s):  
◽  
R. Barnett ◽  
S. J. Warren ◽  
D. J. Mortlock ◽  
J.-G. Cuby ◽  
...  
Keyword(s):  
Luminosity Function ◽  
Near Infrared ◽  
Selection Method ◽  
Early Type ◽  
Data Release ◽  
Rate Of Decline ◽  
Current Record

We provide predictions of the yield of 7 <  z <  9 quasars from the Euclid wide survey, updating the calculation presented in the Euclid Red Book in several ways. We account for revisions to the Euclid near-infrared filter wavelengths; we adopt steeper rates of decline of the quasar luminosity function (QLF; Φ) with redshift, Φ ∝ 10k(z − 6), k = −0.72, and a further steeper rate of decline, k = −0.92; we use better models of the contaminating populations (MLT dwarfs and compact early-type galaxies); and we make use of an improved Bayesian selection method, compared to the colour cuts used for the Red Book calculation, allowing the identification of fainter quasars, down to JAB ∼ 23. Quasars at z >  8 may be selected from Euclid OYJH photometry alone, but selection over the redshift interval 7 <  z <  8 is greatly improved by the addition of z-band data from, e.g., Pan-STARRS and LSST. We calculate predicted quasar yields for the assumed values of the rate of decline of the QLF beyond z = 6. If the decline of the QLF accelerates beyond z = 6, with k = −0.92, Euclid should nevertheless find over 100 quasars with 7.0 <  z <  7.5, and ∼25 quasars beyond the current record of z = 7.5, including ∼8 beyond z = 8.0. The first Euclid quasars at z >  7.5 should be found in the DR1 data release, expected in 2024. It will be possible to determine the bright-end slope of the QLF, 7 <  z <  8, M1450 <  −25, using 8 m class telescopes to confirm candidates, but follow-up with JWST or E-ELT will be required to measure the faint-end slope. Contamination of the candidate lists is predicted to be modest even at JAB ∼ 23. The precision with which k can be determined over 7 <  z <  8 depends on the value of k, but assuming k = −0.72 it can be measured to a 1σ uncertainty of 0.07.

scholarly journals The Composite Image of Sanduleak −69° 202, Candidate Precursor to SN 1987A in the LMC

1988 ◽  
Vol 108 ◽  
pp. 406-407
Author(s):  
Nolan R. Walborn ◽  
Barry M. Lasker ◽  
Victoria G. Laidler ◽  
You-Hua Chu
Keyword(s):  
Near Infrared ◽  
Early Type ◽  
Composite Image ◽  
Sn 1987A ◽  
International Ultraviolet Explorer ◽  
Early Type Stars ◽  
Hr Diagram

The image of Sk −69° 202 was scanned and analyzed on eight (of 32 available) blue through near-infrared photographic plates obtained at the prime focus of the Cerro Tololo Inter-American Observatory 4-meter telescope during 1974–1983. Both intensity syntheses of the image and density differences were derived by means of reference stars from the same plates, including the similar nearby object Sk −69° 203. Several of the density differences are shown in Figure 1. The analysis shows that the 12m blue supergiant in Sk −69° 202 (Star 1) has two companions with V magnitudes, position angles, and separations 315°, 3″ (Star 2) and 115°, 1.″5 (Star 3), respectively. Both companions appear to be early-type stars; there is no evidence for a bright red star in the system. The two companions are responsible for the spectra observed by the International Ultraviolet Explorer following the decline of the SN in the far UV, so that Star 1 has disappeared and was probably the progenitor. The most likely interpretation is that it was a post-red supergiant evolving blueward in the HR diagram.

scholarly journals Stellar population study in early-type galaxies: an approach from the K band

2009 ◽  
Vol 5 (S262) ◽  
pp. 85-88
Author(s):  
Esther Mármol-Queraltó ◽  
Nicolás Cardiel ◽  
P. Sánchez-Blázquez ◽  
S. C. Trager ◽  
R. F. Peletier ◽  
...  
Keyword(s):  
Stellar Population ◽  
Near Infrared ◽  
Optical Measurements ◽  
Early Type ◽  
Spectral Window ◽  
Cluster Galaxies ◽  
Medium Resolution ◽  
Fornax Cluster ◽  
New Generation ◽  
K Band

AbstractA full understanding of the physical properties of integrated stellar systems demands a multiwavelength approach since each spectral window shows us the contribution of different types of stars. However, most of the observational effort in stellar population studies has been focused on the optical range. Now, the new generation of instruments allow us to explore the K band, where RGB and AGB stars dominate the light of the integrated spectra. Here we present a K-band spectroscopic analysis of early-type galaxies in different environments. Our sample comprises 12 field early-type galaxies observed with ISAAC at VLT with medium resolution, and they are compared with 11 Fornax cluster galaxies previously reported by Silva et al. (2008). The clear differences found in the infrared DCO and NaI indices between field and Fornax galaxies are discussed, trying to solve the puzzle formed by the near-infrared and optical measurements.

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