Large-Scale Environment Properties of Narrow-Line Seyfert 1 Galaxies at z < 0.4
The large-scale environment is believed to affect the evolution and intrinsic properties of galaxies. It offers a new perspective on narrow-line Seyfert 1 galaxies (NLS1) which have not been extensively studied in this context before. We study a large and diverse sample of 960 NLS1 galaxies using a...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2017-11-01
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| Series: | Frontiers in Astronomy and Space Sciences |
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| Online Access: | http://journal.frontiersin.org/article/10.3389/fspas.2017.00054/full |
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| author | Emilia Järvelä Emilia Järvelä A. Lähteenmäki A. Lähteenmäki A. Lähteenmäki H. Lietzen |
| author_facet | Emilia Järvelä Emilia Järvelä A. Lähteenmäki A. Lähteenmäki A. Lähteenmäki H. Lietzen |
| author_sort | Emilia Järvelä |
| collection | DOAJ |
| description | The large-scale environment is believed to affect the evolution and intrinsic properties of galaxies. It offers a new perspective on narrow-line Seyfert 1 galaxies (NLS1) which have not been extensively studied in this context before. We study a large and diverse sample of 960 NLS1 galaxies using a luminosity-density field constructed using Sloan Digital Sky Survey. We investigate how the large-scale environment is connected to the properties of NLS1 galaxies, especially their radio loudness. Furthermore, we compare the large-scale environment properties of NLS1 galaxies with other active galactic nuclei (AGN) classes, for example, other jetted AGN and broad-line Seyfert 1 (BLS1) galaxies, to shed light on their possible relations. In general NLS1 galaxies reside in less dense large-scale environments than any of our comparison samples, thus supporting their young age. The average luminosity-density and distribution to different luminosity-density regions of NLS1 sources is significantly different compared to BLS1 galaxies. This contradicts the simple orientation-based unification of NLS1 and BLS1 galaxies, and weakens the hypothesis that BLS1 galaxies are the parent population of NLS1 galaxies. The large-scale environment density also has an impact on the intrinsic properties of NLS1 galaxies; the radio loudness increases with the increasing luminosity-density. However, our results suggest that the NLS1 population is indeed heterogeneous, and that a considerable fraction of them are misclassified. We support a suggested description that the traditional classification based on the radio loudness should be replaced with the division to jetted and non-jetted sources. |
| first_indexed | 2024-04-12T04:48:27Z |
| format | Article |
| id | doaj.art-cc52cf6e381440449b405ef991bec1b1 |
| institution | Directory Open Access Journal |
| issn | 2296-987X |
| language | English |
| last_indexed | 2024-04-12T04:48:27Z |
| publishDate | 2017-11-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Astronomy and Space Sciences |
| spelling | doaj.art-cc52cf6e381440449b405ef991bec1b12022-12-22T03:47:24ZengFrontiers Media S.A.Frontiers in Astronomy and Space Sciences2296-987X2017-11-01410.3389/fspas.2017.00054305708Large-Scale Environment Properties of Narrow-Line Seyfert 1 Galaxies at z < 0.4Emilia Järvelä0Emilia Järvelä1A. Lähteenmäki2A. Lähteenmäki3A. Lähteenmäki4H. Lietzen5Metsähovi Radio Observatory, Aalto University, Espoo, FinlandDepartment of Electronics and Nanoengineering, Aalto University, Espoo, FinlandMetsähovi Radio Observatory, Aalto University, Espoo, FinlandDepartment of Electronics and Nanoengineering, Aalto University, Espoo, FinlandTartu Observatory, Tõravere, EstoniaTartu Observatory, Tõravere, EstoniaThe large-scale environment is believed to affect the evolution and intrinsic properties of galaxies. It offers a new perspective on narrow-line Seyfert 1 galaxies (NLS1) which have not been extensively studied in this context before. We study a large and diverse sample of 960 NLS1 galaxies using a luminosity-density field constructed using Sloan Digital Sky Survey. We investigate how the large-scale environment is connected to the properties of NLS1 galaxies, especially their radio loudness. Furthermore, we compare the large-scale environment properties of NLS1 galaxies with other active galactic nuclei (AGN) classes, for example, other jetted AGN and broad-line Seyfert 1 (BLS1) galaxies, to shed light on their possible relations. In general NLS1 galaxies reside in less dense large-scale environments than any of our comparison samples, thus supporting their young age. The average luminosity-density and distribution to different luminosity-density regions of NLS1 sources is significantly different compared to BLS1 galaxies. This contradicts the simple orientation-based unification of NLS1 and BLS1 galaxies, and weakens the hypothesis that BLS1 galaxies are the parent population of NLS1 galaxies. The large-scale environment density also has an impact on the intrinsic properties of NLS1 galaxies; the radio loudness increases with the increasing luminosity-density. However, our results suggest that the NLS1 population is indeed heterogeneous, and that a considerable fraction of them are misclassified. We support a suggested description that the traditional classification based on the radio loudness should be replaced with the division to jetted and non-jetted sources.http://journal.frontiersin.org/article/10.3389/fspas.2017.00054/fullactive galactic nucleinarrow-line Seyfert 1 galaxieslarge-scale environmentradio loudnessrelativistic jets |
| spellingShingle | Emilia Järvelä Emilia Järvelä A. Lähteenmäki A. Lähteenmäki A. Lähteenmäki H. Lietzen Large-Scale Environment Properties of Narrow-Line Seyfert 1 Galaxies at z < 0.4 Frontiers in Astronomy and Space Sciences active galactic nuclei narrow-line Seyfert 1 galaxies large-scale environment radio loudness relativistic jets |
| title | Large-Scale Environment Properties of Narrow-Line Seyfert 1 Galaxies at z < 0.4 |
| title_full | Large-Scale Environment Properties of Narrow-Line Seyfert 1 Galaxies at z < 0.4 |
| title_fullStr | Large-Scale Environment Properties of Narrow-Line Seyfert 1 Galaxies at z < 0.4 |
| title_full_unstemmed | Large-Scale Environment Properties of Narrow-Line Seyfert 1 Galaxies at z < 0.4 |
| title_short | Large-Scale Environment Properties of Narrow-Line Seyfert 1 Galaxies at z < 0.4 |
| title_sort | large scale environment properties of narrow line seyfert 1 galaxies at z 0 4 |
| topic | active galactic nuclei narrow-line Seyfert 1 galaxies large-scale environment radio loudness relativistic jets |
| url | http://journal.frontiersin.org/article/10.3389/fspas.2017.00054/full |
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