We present new observations of Hα emission in the Hickson compact group 18 (HCG 18), obtained with a scanning Fabry-Perot interferometer. The velocity field does not show motions of individual group members but instead a complex common velocity field for the whole group. The gas distribution is very asymmetric, with clumps of maximum intensity coinciding with the optically brightest knots. Comparing Hα and H I data, we conclude that HCG 18 is not a compact group but instead a large irregular galaxy with several star-forming clumps.

Kinematics and Morphology of Ionized Gas in Hickson Compact Group 18

We present new observations of $H\alpha $ emission in the Hickson Compact Group 18 (HCG 18) obtained with a scanning Fabry-Perot interferometer. The velocity field does not show motions of individual group members but, instead, a complex common velocity field for the whole group. The gas distribution is very asymmetric with clumps of maximum intensity coinciding with the optically brightest knots. Comparing $H\alpha $ and HI data we conclude that HCG 18 is not a compact group but instead a large irregular galaxy with several clumps of star formation.

Kinematics and morphology of ionized gas in Hickson Compact Group 18

We present near-infrared single-star photometry for the low-metallicity blue compact dwarf galaxy VII Zw 403. We achieve limiting magnitudes of F110W ≈ 25.5 and F160W ≈ 24.5 using one of the NICMOS cameras with the Hubble Space Telescope equivalents of the ground-based J and H filters. The data have a high photometric precision (0.1 mag) and are more than 95% complete down to magnitudes of about 23, far deeper than previous ground-based studies in the near-IR. The color-magnitude diagram contains about 1000 point sources. We provide a preliminary transformation of the near-IR photometry into the ground system. We investigate the tip of the red giant branch method in the J and H bands to provide an empirical distance calibration. Combining our result with globular cluster data as well as stellar-evolution models, we recommend MH,TRGB = -5.5(±0.1) for -2.3 < [Fe/H] < -1.5. We proceed to discuss the stellar content of VII Zw 403 using evolutionary tracks as well as a classification scheme based on optical and near-IR colors, and we comment on the detection of asymptotic giant branch stars and the blue Hertzprung gap. We use MH as an indicator of Mbol for red stars after evaluating BCH at low metallicity. We calculate the fractional contribution of individual stars from our color-magnitude diagram to the integrated light of VII Zw 403 and determine which red stellar population dominates the integrated colors. We find that young red supergiants, and young and intermediate-age asymptotic giants, together provide about 50% of the light in I, J, and H bands, whereas the old red giant stars contribute less than 15%. Young, main-sequence stars and blue supergiants account for the remaining light and dominate in V. This explains the difficulties in discerning the nature of blue compact dwarf galaxies when only integrated photometry is available.

A Near-Infrared Stellar Census of the Blue Compact Dwarf Galaxy VII ZW 403

Kinematics of the Ionized Gas in the Irregular Galaxies IC 10 and NGC 4449

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

J. Borissova

Author Tools

Chat about Author

Papers

Kinematics of the Ionized Gas in the Irregular Galaxies IC 10 and NGC 4449