{"title":"低光度活动星系核的喷流辐射","authors":"Gunjan Tomar, N. Gupta, R. Prince","doi":"10.22323/1.444.0947","DOIUrl":null,"url":null,"abstract":"Low-Luminosity Active Galactic Nuclei (LLAGNs) are challenging to study due to their faintness despite occupying 40% of the local Universe. The radiatively inefficient accretion flows that power these LLAGNs are known to be efficient at producing bipolar jets. Multi-wavelength observations of the jets act as a crucial probe of the physical mechanism in these extreme environments. The recent detection of LLAGNs NGC 315 and NGC 4261 in gamma rays by Fermi-LAT allows us to model their multi-wavelength spectral energy distribution (SED) from radio to gamma rays. We find that the synchrotron and synchrotron self-Compton emission from an emission region at sub-parsec scale jet can explain the SEDs up to a few GeV, leaving an excess beyond that. The gamma rays produced by the upscattering of the starlight photons from the host galaxy by the ultra-relativistic electrons at the kilo-parsec scale successfully explain this excess. Thus, similar to luminous AGNs, the electrons in the kilo-parsec jets of LLAGNs are also accelerated to ultra-relativistic energies. The ejection of a discrete knot from another LLAGN, M81*, again suggests similarities in the jet production mechanism for luminous AGNs and LLAGNs. Due to non-detection in gamma rays, we model its multi-wavelength SEDs from radio to X-rays at different epochs during the knot ejection to infer the properties of the jet. We also model the SEDs during other X-ray flaring periods identified from the long-term Swift light curve. As seen in the high-synchrotron-peaked blazars (a sub-class of luminous AGNs), the synchrotron emission from relativistic electrons from a single zone explains the SEDs from radio to X-ray during all states. We present these results and compare the similarities of these jets in LLAGNs with those produced in luminous AGNs","PeriodicalId":448458,"journal":{"name":"Proceedings of 38th International Cosmic Ray Conference — PoS(ICRC2023)","volume":"10 1","pages":"0"},"PeriodicalIF":0.0000,"publicationDate":"2023-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Emission from the jets of Low-luminosity Active Galactic Nuclei\",\"authors\":\"Gunjan Tomar, N. Gupta, R. Prince\",\"doi\":\"10.22323/1.444.0947\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Low-Luminosity Active Galactic Nuclei (LLAGNs) are challenging to study due to their faintness despite occupying 40% of the local Universe. The radiatively inefficient accretion flows that power these LLAGNs are known to be efficient at producing bipolar jets. Multi-wavelength observations of the jets act as a crucial probe of the physical mechanism in these extreme environments. The recent detection of LLAGNs NGC 315 and NGC 4261 in gamma rays by Fermi-LAT allows us to model their multi-wavelength spectral energy distribution (SED) from radio to gamma rays. We find that the synchrotron and synchrotron self-Compton emission from an emission region at sub-parsec scale jet can explain the SEDs up to a few GeV, leaving an excess beyond that. The gamma rays produced by the upscattering of the starlight photons from the host galaxy by the ultra-relativistic electrons at the kilo-parsec scale successfully explain this excess. Thus, similar to luminous AGNs, the electrons in the kilo-parsec jets of LLAGNs are also accelerated to ultra-relativistic energies. The ejection of a discrete knot from another LLAGN, M81*, again suggests similarities in the jet production mechanism for luminous AGNs and LLAGNs. Due to non-detection in gamma rays, we model its multi-wavelength SEDs from radio to X-rays at different epochs during the knot ejection to infer the properties of the jet. We also model the SEDs during other X-ray flaring periods identified from the long-term Swift light curve. As seen in the high-synchrotron-peaked blazars (a sub-class of luminous AGNs), the synchrotron emission from relativistic electrons from a single zone explains the SEDs from radio to X-ray during all states. We present these results and compare the similarities of these jets in LLAGNs with those produced in luminous AGNs\",\"PeriodicalId\":448458,\"journal\":{\"name\":\"Proceedings of 38th International Cosmic Ray Conference — PoS(ICRC2023)\",\"volume\":\"10 1\",\"pages\":\"0\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2023-08-14\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Proceedings of 38th International Cosmic Ray Conference — PoS(ICRC2023)\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.22323/1.444.0947\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Proceedings of 38th International Cosmic Ray Conference — PoS(ICRC2023)","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.22323/1.444.0947","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
摘要
低光度活动星系核(llagn)尽管占据了局部宇宙的40%,但由于它们的微弱,研究起来很有挑战性。为这些llagn提供动力的辐射效率低下的吸积流在产生双极射流方面是有效的。对喷流的多波长观测是研究这些极端环境中物理机制的重要手段。最近Fermi-LAT在伽马射线中探测到的LLAGNs NGC 315和NGC 4261使我们能够模拟它们从射电到伽马射线的多波长光谱能量分布(SED)。我们发现,在亚秒差距尺度射流的发射区域中,同步加速器和同步加速器自康普顿发射可以解释高达几个GeV的SEDs,而在此之外还有多余的部分。来自宿主星系的星光光子在千秒差距尺度上被超相对论性电子向上散射而产生的伽马射线成功地解释了这种过剩。因此,与发光agn类似,llagn的千秒差距喷流中的电子也被加速到超相对论能量。从另一个LLAGN M81*中喷射出一个离散结,再次表明发光agn和LLAGN的射流产生机制相似。由于在伽马射线中没有检测到,我们在结喷射期间的不同时期对其从无线电到x射线的多波长SEDs进行了建模,以推断喷流的性质。我们还模拟了从长期斯威夫特光曲线确定的其他x射线耀斑时期的SEDs。正如在高同步加速器峰值的耀变体(发光agn的一个子类)中看到的那样,来自单个区域的相对论电子的同步加速器发射解释了在所有状态下从无线电到x射线的SEDs。我们提出了这些结果,并比较了这些喷流在llagn中与在发光agn中产生的相似性
Emission from the jets of Low-luminosity Active Galactic Nuclei
Low-Luminosity Active Galactic Nuclei (LLAGNs) are challenging to study due to their faintness despite occupying 40% of the local Universe. The radiatively inefficient accretion flows that power these LLAGNs are known to be efficient at producing bipolar jets. Multi-wavelength observations of the jets act as a crucial probe of the physical mechanism in these extreme environments. The recent detection of LLAGNs NGC 315 and NGC 4261 in gamma rays by Fermi-LAT allows us to model their multi-wavelength spectral energy distribution (SED) from radio to gamma rays. We find that the synchrotron and synchrotron self-Compton emission from an emission region at sub-parsec scale jet can explain the SEDs up to a few GeV, leaving an excess beyond that. The gamma rays produced by the upscattering of the starlight photons from the host galaxy by the ultra-relativistic electrons at the kilo-parsec scale successfully explain this excess. Thus, similar to luminous AGNs, the electrons in the kilo-parsec jets of LLAGNs are also accelerated to ultra-relativistic energies. The ejection of a discrete knot from another LLAGN, M81*, again suggests similarities in the jet production mechanism for luminous AGNs and LLAGNs. Due to non-detection in gamma rays, we model its multi-wavelength SEDs from radio to X-rays at different epochs during the knot ejection to infer the properties of the jet. We also model the SEDs during other X-ray flaring periods identified from the long-term Swift light curve. As seen in the high-synchrotron-peaked blazars (a sub-class of luminous AGNs), the synchrotron emission from relativistic electrons from a single zone explains the SEDs from radio to X-ray during all states. We present these results and compare the similarities of these jets in LLAGNs with those produced in luminous AGNs