Based on SITELLE spectroscopy, we studied the ionised gas emission for the 175 H$α$ emission regions in the Stephan's Quintet (SQ). A detailed analysis is performed of the star formation rate (SFR), oxygen abundance (O/H), and nitrogen-to-oxygen abundance ratio (N/O) of the SQ regions, to explore the provenance and evolution of this complex structure. According to the BPT diagram, we found 91 HII, 17 composite, and 7 active galactic nucleus-like regions in SQ. Several regions are compatible with fast shocks models without a precursor for solar metallicity and low density (n=0.1 cm$^{-3}$), with velocities between 175 - 300 km s$^{-1}$. We derived the total SFR in SQ (log(SFR/M$_\odot\,yr^{-1}$=0.496); starburst A and B provide 28% and 9% of the total SFR, and 45% comes from the regions with a radial velocity lower than 6160 km s$^{-1}$. For this reason, we assume that the material prior to the collision with the new intruder (NI) does not show a high SFR, and therefore SQ was apparently quenched. When considering the integrated SFR for the whole SQ and the NI, we found that both zones have a SFR consistent with those obtained in the SDSS star-forming galaxies. At least two chemically different gas components cohabit in SQ where, on average, the regions with high radial velocities (v$>$6160 km s$^{-1}$) have lower values of O/H and N/O than those with low radial velocities (v$\leq$6160 km s$^{-1}$). The values found for the line ratios, O/H, and N/O for the southern debris region and the northernmost tidal tail, are compatible with regions belonging to the outer part of the galaxies. We highlight the presence of inner-outer variation for O/H and some emission line ratios along the NI strands and the young tidal tail south strand. Finally, the SQ H$α$ regions are outside the galaxies because the interactions have dispersed the gas to the peripheral zones.
The spatial distribution and physical sizes of star forming clumps at the smallest scales provide valuable information on hierarchical star formation (SF). In this context, we report the sites of ongoing SF at ~120 pc along the interacting galaxies in Stephan's Quintet (SQ) compact group using AstroSat-UVIT and JWST data. Since ultraviolet radiation is a direct tracer of recent SF, we identified star forming clumps in this compact group from the FUV imaging which we used to guide us to detect star forming regions on JWST IR images. The FUV imaging reveals star forming regions within which we d…
Regular magnetic fields are frequently found within and in the outskirts of galaxies, but their presence, properties, and origin has not yet been established for galaxy groups. On the basis of broadband radio polarimetric imaging with the Westerbork Synthesis Radio Telescope (WSRT), we made use of Rotation Measure Synthesis to disentangle contributions from magnetic fields on various scales for several polarised radio sources inside, behind, or in the vicinity of the Stephan's Quintet (HCG92, SQ). We recognise the signature of a large-scale, genuinely regular, magnetised screen, seemingly cons…
Stephan's Quintet (SQ), the prototypical compact group of galaxies in the local Universe, has been observed with the imaging Fourier transform spectrometer SITELLE, attached to the CFHT, to perform a deep search for intergalactic star-forming emission. We present the extended ionised gaseous structures detected and analyse their kinematical properties. The large field of view (11'x11') and the spectral ranges of SITELLE have allowed a thorough study of the entire galaxy system, its interaction history and the main properties of the ionised gas. The observations have revealed complex 3D strands…
Stephan's Quintet, a compact group of galaxies, is often used as a laboratory to study a number of phenomena, including physical processes in the interstellar medium, star formation, galaxy evolution, and the formation of fossil groups. As such, it has been subject to intensive multi-wavelength observation campaigns. Yet, models lack constrains to pin down the role of each galaxy in the assembly of the group. We revisit here this system with multi-band deep optical images obtained with MegaCam on the Canada-France-Hawaii Telescope (CFHT), focusing on the detection of low surface brightness (LS…
An Analysis of AGN Feedback in the Compact Galaxy Group Stephan's Quintet
Georgia State University（佐治亚州立大学）；Space Telescope Science Institute（太空望远镜科学研究所）；AURA for ESA（欧洲空间局天文研究联盟）；Georgia Institute of Technology（佐治亚理工学院）；University of Groningen（格罗宁根大学）；Tufts University（塔夫茨大学）
Stephan's Quintet (SQ, distance=85$\pm$6 Mpc) is unique among compact groups of galaxies. Observations have previously shown that interactions between multiple members, including a high-speed intruder galaxy currently colliding into the intragroup medium, have likely generated tidal debris in the form of multiple gaseous and stellar filaments, the formation of tidal dwarfs and intragroup-medium starbursts, as well as widespread intergalactic shocked gas. The details and timing of the interactions/collisions remain poorly understood because of the multiple nature. Here we report atomic hydrogen…
Near- to Far-Infrared Spectral Energy Distribution Analysis of Interacting Galaxies in Hickson Compact Groups 56 and Stephan's Quintet (HCG 92)
The University of Tokyo（东京大学）；Université Paris-Saclay, Université Paris Cité, CEA, CNRS, AIM（巴黎萨克雷大学、巴黎西岱大学、法国原子能与替代能源委员会、法国国家科学研究中心、天体物理信息与建模实验室）；QunaSys Europe（QunaSys欧洲公司）
Powerful H2 Line Cooling in Stephan's Quintet II. Group-wide Gas and Shock Modeling of the Warm H2 and a Comparison with [CII]157.7um Emission and Kinematics
A MeerKAT view of the Neutral Atomic Gas in Stephan's Quintet
Naval Research Laboratory（海军研究实验室）；Caltech/IPAC（加州理工学院/IPAC）；Chinese Academy of Sciences South America Center for astronomy, National Astronomical Observatories, CAS（中国科学院南美天文中心，国家天文台，中科院）；National astronomical Observatories（国家天文台）
Stephan's Quintet (SQ) is a nearby compact galaxy group and a perfect laboratory for studying the process of galaxy evolution through galaxy harassment and interaction. By analysing the kinematics of SQ we aim to provide an increased understanding of the group, the history of the interactions, their cause and effect, and the details regarding the physical processes occurring as galaxies interact. We have studied the ionised gas and stellar kinematics using the Large Binocular Telescope, and the molecular gas kinematics via CO using the IRAM 30m. Large areas of the group have been mapped and an…
We present Hubble Space Telescope Cosmic Origin Spectrograph (COS) UV line spectroscopy and integral-field unit (IFU) observations of the intra-group medium in Stephan's Quintet (SQ). SQ hosts a 30 kpc long shocked ridge triggered by a galaxy collision at a relative velocity of 1000 km/s, where large amounts of molecular gas coexist with a hot, X-ray emitting, plasma. COS spectroscopy at five positions sampling the diverse environments of the SQ intra-group medium reveals very broad (2000 km/s) Ly$α$ line emission with complex line shapes. The Ly$α$ line profiles are similar to or much broader…
A radio continuum view of Stephan's Quintet: age, dynamics and origin of the shock
INAF-IRA（意大利国家天体物理研究所雷焦艾米利亚分部）；Leiden Observatory, Leiden University（莱顿大学莱顿天文台）；Universidad de Granada（格拉纳达大学）；Instituto Carlos I de Física Teórica y Computacional（卡洛斯一世理论与计算物理研究所）
Molecular Gas Structure and Star Formation Diversity in Stephan's Quintet Revealed by ACA CO(1-0) Mapping
Osaka Metropolitan University（大阪公立大学）；Osaka Electro-Communication University（大阪电通大学）；The University of Tokyo（东京大学）；Kogakuin University（工学馆大学）；National Astronomical Observatory of Japan（日本国立天文台）；Graduate University for Advanced Studies, SOKENDAI（日本高级研究院）；Niigata University（新潟大学）
Shock-Enhanced C+ Emission and the Detection of H2O from Stephan's Quintet's Group-Wide Shock using Herschel
我们首次用赫歇尔光谱探测到了[OI]63和[CII]158微米的精细结构跃迁，以及斯蒂芬五重奏中35 x 15 kpc^2的受激星系际暗条中的一条para-H2O谱线。这条暗条被认为是当一个高速入侵者与星团内气体碰撞时形成的。PACS光谱仪的观测提供了宽（> 1000 km s^-1）的发光[CII]谱线轮廓以及较暗的[OI] 63微米发射的证据。SPIRE FTS观测揭示了细丝中几个位置的p-H2O（111-000）跃迁的水发射，但没有其他分子线。H2O谱线很窄，可能与密度较大的中速气体经历最强的冲击加热有关。[CII]/PAH（tot）和[CII]/FIR比率太大，无法通过PDR中的正常光电加热来解释。也可以排除HII区激发或X射线/宇宙射线加热。观测结果得出的结论是，大部分分子气体是扩散和温暖的。我们建议，[CII]，[OI]和暖H2线的发射是由一个湍流级联，其中的动能从星系碰撞与IGM耗散到小尺度和低速度，通过冲击和湍流涡旋。低速磁震可以帮助解释[CII]/[OI]比值和观察到的相对较高的[CII]/H2比值。发现[CII]发射可以增强，在大规模的湍流区域的碰撞环境中的影响的解释[CII]发射在高z星系。
New insights on Stephan's Quintet: exploring the shock in three dimensions
我们进行了IFU光谱的三个点和附近的SQ冲击。我们使用PMAS的3.5米卡拉尔阿尔托望远镜获得的发射线，提供洞察气体的物理性质的措施。Hα和[NII]6548、6583 A发射线在许多spaxels中的严重混合需要至少两个运动学分量的假设，以便提取各条线的通量。我们研究的主要结果包括：（a）在新的入侵者速度范围5400- 6000公里/秒内探测到离散发射特征，显示出与HII区一致的特性，（b）探测到速度在5800- 6300公里/秒范围内的低速成分，其性质类似于太阳金属丰度冲击气体;与低金属量冲击气体的性质一致。这两个冲击分量被解释为NGC 7318 b新侵入者与其路径上的碎片场碰撞的产物，这产生了一种复杂的电离气体结构，其中有几种具有不同运动学和物理特性的成分共存，尽管与NGC 7318 b有关的原始ISM的一部分仍然存在，并且保持不变。我们的观测结果表明，低速电离分量可能在新的入侵者碰撞之前就已经存在，并且可能与Williams等人（2002）的NW-LV HI分量有关。高速电离分量可能填补了SQ-A和NGC 7319潮丝中观测到的HI复合体之间的空隙（NW-HV，Arc-N和Arc-S in Williams et al. 2002）。
We present ALMA observations at a spatial resolution of 0.2 arcsec (60 pc) of CO emission from the Taffy galaxies (UGC 12914/5). The observations are compared with narrow-band Pa$α$, mid-IR, radio continuum and X-ray imaging, plus optical spectroscopy. The galaxies have undergone a recent head-on collision, creating a massive gaseous bridge which is known to be highly turbulent. The bridge contains a complex web of narrow molecular filaments and clumps. The majority of the filaments are devoid of star formation, and fall significantly below the Kennicutt-Schmidt relationship for normal galaxie…
