H II regions as extragalactic distance indicators. I - Observations and structural considerations

1979 ◽  
Vol 228 ◽  
pp. 394 ◽  
Author(s):  
R. C., Jr. Kennicutt
Keyword(s):  
H Ii Regions ◽  
Distance Indicators

Magellanic Cloud Eclipsing Binaries: Primary Distance Indicators

1999 ◽  
Vol 190 ◽  
pp. 563-566
Author(s):  
J. D. Pritchard ◽  
W. Tobin ◽  
J. V. Clausen ◽  
E. F. Guinan ◽  
E. L. Fitzpatrick ◽  
...  
Keyword(s):  
New Zealand ◽  
Magellanic Cloud ◽  
Eclipsing Binaries ◽  
Fundamental Parameters ◽  
Distance Indicators

Our collaboration involves groups in Denmark, the U.S.A. Spain and of course New Zealand. Combining ground-based and satellite (IUEandHST) observations we aim to determine accurate and precise stellar fundamental parameters for the components of Magellanic Cloud Eclipsing Binaries as well as the distances to these systems and hence the parent galaxies themselves. This poster presents our latest progress.

The DIVING3D Project: Analysis of the nuclear region of Early-type Galaxies

2020 ◽  
Vol 15 (S359) ◽  
pp. 454-456
Author(s):  
T. V. Ricci ◽  
J. E. Steiner ◽  
R. B. Menezes
Keyword(s):  
Emission Lines ◽  
H Ii Regions ◽  
Sample Type ◽  
Early Type ◽  
Integral Field Spectroscopy ◽  
Project Analysis ◽  
Line Region ◽  
Field Unit ◽  
Integral Field

AbstractIn this work, we present preliminary results regarding the nuclear emission lines of a statistically complete sample of 56 early-type galaxies that are part of the Deep Integral Field Spectroscopy View of Nuclei of Galaxies (DIVING3D) Project. All early type galaxies (ETGs) were observed with the Gemini Multi-Object Spectrograph Integral Field Unit (GMOS-IFU) installed on the Gemini South Telescope. We detected emission lines in 93% of the sample, mostly low-ionization nuclear emission-line region galaxies (LINERs). We did not find Transition Objects nor H II regions in the sample. Type 1 objects are seen in ∼23% of the galaxies.

scholarly journals Electron temperatures in the Galactic H ii regions W43 and M17

1996 ◽  
Vol 281 (1) ◽  
pp. 239-244 ◽  
Author(s):  
Ravi Subrahmanyan ◽  
W. M. Goss
Keyword(s):  
H Ii Regions

scholarly journals The effects of peculiar velocities in SN Ia environments on the local H0 measurement

2020 ◽  
Vol 500 (3) ◽  
pp. 3728-3742
Author(s):  
Thomas M Sedgwick ◽  
Chris A Collins ◽  
Ivan K Baldry ◽  
Philip A James
Keyword(s):  
Hubble Constant ◽  
Density Parameter ◽  
Host Galaxies ◽  
Peculiar Velocities ◽  
Standard Candle ◽  
Modern Cosmology ◽  
Type Ia ◽  
The Difference ◽  
Ia Supernovae ◽  
Distance Indicators

ABSTRACT The discrepancy between estimates of the Hubble constant (H0) measured from local (z ≲  0.1) scales and from scales of the sound horizon is a crucial problem in modern cosmology. Peculiar velocities (vpec) of standard candle distance indicators can systematically affect local H0 measurements. We here use 2MRS galaxies to measure the local galaxy density field, finding a notable z  <  0.05 underdensity in the SGC-6dFGS region of 27  ±  2 per cent. However, no strong evidence for a ‘Local Void’ pertaining to the full 2MRS sky coverage is found. Galaxy densities are used to measure a density parameter, Δϕ+−, which we introduce as a proxy for vpec that quantifies density gradients along a supernova (SN) line of sight. Δϕ+− is found to correlate with local H0 estimates from 88 Pantheon Type Ia supernovae (SNe Ia; 0.02  <  z  <  0.05). Density structures on scales of ∼50 Mpc are found to correlate strongest with H0 estimates in both the observational data and in mock data from the MDPL2-Galacticus simulation. Using trends of H0 with Δϕ+−, we can correct for the effects of density structure on local H0 estimates, even in the presence of biased vpec. However, the difference in the inferred H0 estimate with and without the peculiar velocity correction is limited to < 0.1  per cent. We conclude that accounting for environmentally induced peculiar velocities of SN Ia host galaxies does not resolve the tension between local and CMB-derived H0 estimates.

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