利用 ALMA 观测数据，本研究发现 Henize 2-10 矮星系中黑洞周围的分子气体受双极外流激波作用而高度激发，为黑洞正反馈触发恒星形成提供了证据。
摘要：
Henize 2-10 是一个矮星暴星系，宿主着一个质量约为 $10^{6}~M_{\odot}$ 的黑洞（BH），该黑洞正在驱动电离外流并在星系中心约 100 pc 范围内触发恒星形成。在此，我们展示了 ALMA 从 99 到 340 GHz 的连续谱观测，以及分子 CO (1-0, 3-2)、HCN (1-0, 3-2) 和 HCO$^{+}$ (1-0, 3-2) 的谱线观测，重点关注该黑洞及其邻近区域。结合文献中的厘米波射电测量结果，我们表明该黑洞的能谱分布从 1.4 到约 340 GHz 由同步辐射主导，谱指数为 $\alpha\approx-0.5$。我们分析了谱线数据，在黑洞周围识别出一个具有与周围区域不同速度的拉长分子气体结构。该分子气体结构的物理尺度约为 $130~{\rm pc}\times30$ pc，分子气体质量约为 $10^{6}~M_{\odot}$。尽管该区域普遍存在丰富的分子气体，但黑洞的位置显著偏离强度峰值，这可能解释了为何该黑洞以极低的爱丁顿比辐射。我们对空间分辨的 CO J=3-2 与 J=1-0 谱线比的分析表明，黑洞附近的 CO 气体处于高度激发态，尤其是在黑洞外流与触发恒星形成区域的交界处。这表明冷分子气体正受到黑洞双极外流的激波作用，支持了黑洞正反馈的观点。
英文摘要：
Henize 2-10 is a dwarf starburst galaxy hosting a $\sim10^{6}~M_{\odot}$ black hole (BH) that is driving an ionized outflow and triggering star formation within the central $\sim100$ pc of the galaxy. Here we present ALMA continuum observations from 99 to 340 GHz, as well as spectral line observations of the molecules CO (1-0, 3-2), HCN (1-0, 3-2), and HCO$^{+}$ (1-0, 3-2), with a focus on the BH and its vicinity. Incorporating cm-wave radio measurements from the literature, we show that the spectral energy distribution of the BH is dominated by synchrotron emission from 1.4 to~340 GHz with a spectral index of $α\approx-0.5$. We analyze the spectral line data and identify an elongated molecular gas structure around the BH with a velocity distinct from the surrounding regions. The physical extent of this molecular gas structure is $\approx130~{\rm pc}\times30$ pc and the molecular gas mass is $\sim10^{6}~M_{\odot}$. Despite an abundance of molecular gas in this general region, the position of the BH is significantly offset from the peak intensity, which may explain why the BH is radiating at a very low Eddington ratio. Our analysis of the spatially-resolved line ratio between CO J=3-2 and J=1-0 implies that the CO gas in the vicinity of the BH is highly excited, particularly at the interface between the BH outflow and the regions of triggered star formation. This suggests that the cold molecular gas is being shocked by the bipolar outflow from the BH, supporting the case for positive BH feedback.
We present new ${ }^{12}$CO(J=1-0) observations of Henize 2-10, a blue compact dwarf galaxy about 8.7 Mpc away, taken with the Atacama Large Millimeter Array. These are the highest spatial and spectral resolution observations, to date, of the molecular gas in this starburst galaxy. We measure a molecular mass of $1.2\times10^8 M_\odot$ in Henize 2-10, and most of the molecular gas is contained within a region having a size of about 310 pc. We use the CPROPS algorithm to identify 119 resolved giant molecular clouds distributed throughout the galaxy, and the molecular gas contained within these …
Black hole driven outflows have been observed in some dwarf galaxies with active galactic nuclei (1), and likely play a role in heating and expelling gas (thereby suppressing star formation), as they do in larger galaxies (2). The extent to which black hole outflows can trigger star formation in dwarf galaxies is unclear, because work in this area has hitherto focused on massive galaxies and the observational evidence is scarce (3,4,5). Henize 2-10 is a dwarf starburst galaxy previously reported to have a central massive black hole (6,7,8,9), though that interpretation has been disputed since …
We present ALMA CO(3-2) observations at 0.3 arcsec resolution of He2-10, a starburst dwarf galaxy and possible high-z galaxy analogue. The warm dense gas traced by CO(3--2) is found in clumpy filaments that are kinematically and spatially distinct. The filaments have no preferred orientation or direction; this may indicate that the galaxy is not evolving into a disk galaxy. Filaments appear to be feeding the active starburst; the velocity field in one filament suggests acceleration onto an embedded star cluster. The relative strengths of CO(3-2) and radio continuum vary strongly on decaparsec …
We present an analysis of the X-ray spectrum and long-term variability of the nearby dwarf starburst galaxy Henize 2-10. Recent observations suggest that this galaxy hosts an actively accreting black hole with mass ~10^6 M_sun. The presence of an AGN in a low-mass starburst galaxy marks a new environment for active galactic nuclei (AGNs), with implications for the processes by which "seed" black holes may form in the early Universe. In this paper, we analyze four epochs of X-ray observations of Henize 2-10, to characterize the long-term behavior of its hard nuclear emission. We analyze observa…
We present results of a set of $N$-body simulations to model the future evolution of the 11 young massive clusters hosted in the central region of the dwarf starburst galaxy Henize 2-10, which contains at its center a massive black hole with a mass $M_{\rm BH} \simeq 2\times 10^6$ M$_\odot$. Nuclear star clusters are present in a great quantity of galaxies of mass similar to Henize 2-10. Our results \citep{ASCD15} show that the orbital decay and merging of the Henize 2-10 clusters will likely lead to the formation of a nuclear star cluster with mass $M_{\rm NSC} \simeq 4-6 \times 10^6$ M$_\odo…
The rate of star formation both in the Galaxy and in external galaxies should be related to the physical properties of the molecular clouds from which stars form. This is expected for the starbursts found both in irregular galaxies and in some mergers. The dwarf galaxy Henize 2-10 is particularly interesting in this context as it shows a number of newly formed Super Star Clusters (SSCs) associated with a very rich molecular environment. We present a high angular resolution study of the molecular gas associated with the SSCs with the aim of deriving the physical properties of the parent molecul…
Dwarf galaxies are ideal laboratories to study the physics of the interstellar medium (ISM). Emission lines have been widely used to this aim. Retrieving the full information encoded in the spectra is therefore essential. This can be efficiently and reliably done using Machine Learning (ML) algorithms. Here, we apply the ML code GAME to MUSE (Multi Unit Spectroscopic Explorer) and PMAS (Potsdam Multi Aperture Spectrophotometer) Integral Field Unit (IFU) observations of two nearby Blue Compact Galaxies (BCGs): Henize 2-10 and IZw18. We derive spatially resolved maps of several key ISM physical …
A candidate accreting massive black hole (BH) with M_BH ~ 10^6 Msun has recently been identified at the center of the dwarf starburst galaxy Henize 2-10 (He 2-10). This discovery offers the first possibility of studying a growing BH in a nearby galaxy resembling those in the earlier universe, and opens up a new class of host galaxies to search for the smallest supermassive BHs. Here we present very long baseline interferometry observations of He 2-10 taken with the Long Baseline Array (LBA) at 1.4 GHz with an angular resolution of ~0.1" x 0.03". A single compact radio source is detected at the…
We present ALMA observations of the dwarf starburst galaxy Henize 2-10 in combination with previous SMA CO observations to probe the molecular environments of natal super star clusters. These observations include the HCO$^+$(1-0), HCN(1-0), HNC(1-0), and CCH(1-0) molecular lines, as well as 88 GHz continuum with a spatial resolution of $1''.7\times 1''.6$. After correcting for the contribution from free-free emission to the 88 GHz continuum flux density ($\sim$ 60% of the 88 GHz emission), we derive a total gas mass for He~2-10 of $M_{gas} = 4-6\times10^8$ M$_{\odot}$, roughly 5-20% of the dyn…
We report ALMA observations of $^{12}$CO(3-2) and $^{13}$CO(3-2) in the gas-poor dwarf galaxy NGC 5253. These 0.3"(5.5 pc) resolution images reveal small, dense molecular gas clouds that are located in kinematically distinct, extended filaments. Some of the filaments appear to be falling into the galaxy and may be fueling its current star formation. The most intense CO(3-2) emission comes from the central $\sim$100 pc region centered on the luminous radio-infrared HII region known as the supernebula. The CO(3-2) clumps within the starburst region are anti-correlated with H$α$ on $\sim$5 pc sca…
Properties of the cold interstellar medium of low-metallicity galaxies are not well-known due to the faintness and extremely small scale on which emission is expected. We present deep ALMA band 6 (230GHz) observations of the nearby, low-metallicity (12 + log(O/H) = 7.25) blue compact dwarf galaxy SBS0335-052 at an unprecedented resolution of 0.2 arcsec (52 pc). The 12CO J=2-1 line is not detected and we report a 3-sigma upper limit of LCO(2-1) = 3.6x10^4 K km/s pc^2. Assuming that molecular gas is converted into stars with a given depletion time, ranging from 0.02 to 2 Gyr, we find lower limit…
The physical mechanisms for starburst or quenching in less massive ($M_* < 10^{10} M_{\odot}$) galaxies are unclear. The merger is one of the inescapable processes referred to as both starburst and quenching in massive galaxies. However, the effects of the merger on star formation in dwarf galaxies and their evolution results are still uncertain. We aim to explore how to trigger and quench star formation in dwarf galaxies by studying the metal-poor gas-rich dwarf mergers based on the multi-band observations at a spatial resolution of $\sim$ 460 pc. We use the archival data of ALMA (band 3, 8) …
We estimate the mass of the intermediate-mass black hole at the heart of the dwarf elliptical galaxy NGC 404 using Atacama Large Millimeter/submillimeter Array (ALMA) observations of the molecular interstellar medium at an unprecedented linear resolution of ~0.5 pc, in combination with existing stellar kinematic information. These ALMA observations reveal a central disc/torus of molecular gas clearly rotating around the black hole. This disc is surrounded by a morphologically and kinematically complex flocculent distribution of molecular clouds, that we resolve in detail. Continuum emission is…
We present high-spatial-resolution ($\sim 0\farcs2$, or $\sim$3\,pc) CO(2--1) observations of the nearest young starburst dwarf galaxy, NGC\,5253, taken with the Atacama Large Millimeter/submillimeter Array. We have identified 118 molecular clouds with average values of 4.3\,pc in radius and 2.2\,\kms\, in velocity dispersion, which comprise the molecular cloud complexes observed previously with $\sim$100\,pc resolution. We derive for the first time in this galaxy the $I{\rm (CO)}$--$N$(H$_2$) conversion factor, $X$ = $4.1^{+5.9}_{-2.4}\times10^{20}$\,cm$^{-2}$(K\,\kms)$^{-1}$, based on the vi…
Tidal dwarf galaxies (TDGs) are gravitationally bound condensations of gas and stars formed during galaxy interactions. Here we present multi-configuration ALMA observations of J1023+1952, a TDG in the interacting system Arp 94, where we resolve CO(2-1) emission down to giant molecular clouds (GMCs) at 0.64" ~ 45pc resolution. We find a remarkably high fraction of extended molecular emission (~80-90%), which is filtered out by the interferometer and likely traces diffuse gas. We detect 111 GMCs that give a similar mass spectrum as those in the Milky Way and other nearby galaxies (a truncated p…
We present ALMA continuum and spectral line observations of the young Brown Dwarf rho-Oph 102 at about 0.89 mm and 3.2 mm. We detect dust emission from the disk at these wavelengths and derive an upper limit on the radius of the dusty disk of ~ 40 AU. The derived variation of the dust opacity with frequency in the mm provides evidence for the presence of mm-sized grains in the disk outer regions. This result demonstrates that mm-grains are found even in the low density environments of Brown Dwarf disks and challenges our current understanding of dust evolution in disks. The CO map at 345 GHz c…
The study of the properties of disks around young brown dwarfs can provide important clues on the formation of these very low-mass objects and on the possibility of forming planetary systems around them. The presence of warm dusty disks around brown dwarfs is well known, based on near- and mid-infrared studies. High angular resolution observations of the cold outer disk are limited; we used ALMA to attempt a first survey of young brown dwarfs in the $ρ$-Oph star-forming region. All 17 young brown dwarfs in our sample were observed at 890 $μ$m in the continuum at $\sim0.\!^{\prime\prime}5$ angu…
We combine data from ALMA and MUSE to study the resolved (~300 pc scale) star formation relation (star formation rate vs. molecular gas surface density) in cluster galaxies. Our sample consists of 9 Fornax cluster galaxies, including spirals, ellipticals, and dwarfs, covering a stellar mass range of ~10^8.8 - 10^11 M_Sun. CO(1-0) and extinction corrected Halpha were used as tracers for the molecular gas mass and star formation rate, respectively. We compare our results with Kennicutt (1998) and Bigiel et al. (2008). Furthermore, we create depletion time maps to reveal small-scale variations in…
The JWST and ALMA view of local dwarf Pox 186: Evidence of stripped binaries driving a hard radiation field and little cold molecular gas resulting in high star-formation efficiency
AURA for European Space Agency (ESA), ESA Office, Space Telescope Science Institute（美国大学研究协会（为欧洲空间局）、欧洲空间局办公室、太空望远镜科学研究所）；Astrophysics Research Institute, Liverpool John Moores University（利物浦约翰摩尔斯大学天体物理研究所）；Space Telescope Science Institute（太空望远镜科学研究所）；Centro de Astrobiología (CAB), CSIC-INTA（天文生物学中心（CAB），西班牙国家科学技术研究委员会-国家航空航天技术研究所）；Cosmic Dawn Center (DAWN)（宇宙黎明中心）；AIM, CEA, CNRS, Université Paris-Saclay, Université Paris Diderot, Sorbonne Paris Cité（天体物理学与图像实验室，法国原子能和替代能源委员会，法国国家科学研究中心，巴黎萨克雷大学，巴黎第七大学，索邦巴黎城市大学）；Stockholm University（斯德哥尔摩大学）
The first steps toward planet formation involve the coagulation of small microscopic grains into larger and larger pebbles and rocks in gas-rich disks around young stars and brown dwarfs. Observations in the sub-millimeter can trace mm/cm-sized pebbles in the outer disks, and investigate the mechanisms of coagulation/fragmentation and radial migration of these solids. These represent key, yet not fully understood ingredients for our understanding of the formation of planetesimals, the building blocks of planets. Here we present the first results from an observational program using the ALMA and…
In this work we present ALMA continuum observations at 880 $μ$m of 30 sub-mm cores previously identified with APEX/LABOCA at 870$μ$m in the Barnard 30 cloud. The main goal is to characterize the youngest and lowest mass population in the cloud. As a result, we report the detection of five (out of 30) spatially unresolved sources with ALMA, with estimated masses between 0.9 and 67 M$_{\rm Jup}$. From these five sources, only two show gas emission. The analysis of multi-wavelength photometry from these two objects, namely B30-LB14 and B30-LB19, is consistent with one Class II- and one Class I lo…
This paper presents our observational attempts to precisely measure the central mass of a proto-brown dwarf candidate, L328-IRS, in order to investigate whether L328-IRS is in the substellar mass regime. Observations were made for the central region of L328-IRS with the dust continuum and CO isotopologue line emission at ALMA band 6, discovering the detailed outflow activities and a deconvolved disk structure of a size of $\sim$87 AU $\times$ 37 AU. We investigated the rotational velocities as a function of the disk radius, finding that its motions between 130 AU and 60 AU are partially fitted…
We present the observational evidence of a pseudo-disc around the proto-brown dwarf Mayrit 1701117, the driving source of the large-scale HH~1165 jet. Our analysis is based on ALMA $^{12}$CO (2-1) line and 1.37 mm continuum observations at an angular resolution of $\sim$0.4$^{\prime\prime}$. The pseudo-disc is a bright feature in the CO position-velocity diagram (PVD), elongated in a direction perpendicular to the jet axis, with a total (gas+dust) mass of $\sim$0.02 M$_{\odot}$, size of 165-192 AU, and a velocity spread of $\pm$2 km s$^{-1}$. The large velocity gradient is a combination of inf…
We present single-dish (sub)millimeter observations of gas and dust in the Galactic high-mass star-forming region G19.61-0.23, with the aim of studying the large-scale properties and physical conditions of the molecular gas across the region. The final aim is to compare the large-scale (about 100 pc) properties with the small-scale (about 3 pc) properties and to consider possible implications for extragalactic studies. We have mapped CO isotopologues in the J=1-0 transition using the FCRAO-14m telescope and the J=2-1 transition using the IRAM-30m telescope. We have also used data from the ATLA…
We present subarcsecond images of submillimeter CO and continuum emission from a local galaxy forming massive star clusters: the blue compact dwarf galaxy II Zw 40. At $\sim$0.4" resolution (20 pc), the CO(3-2), CO(1-0), 3mm and 870$μ$m continuum maps illustrate star formation on the scales of individual molecular clouds. Dust contributes about a third of the 870$μ$m continuum emission, with free-free accounting for the rest. On these scales, there is not a good correspondence between gas, dust, and free-free emission. Dust continuum is enhanced toward the star-forming region as compared to th…
We present Atacama Large Millimeter/submillimeter Array (ALMA) Cycle 0 Band 7 observations of an extremely metal-poor dwarf starburst galaxy in the Local Universe, SBS0335-052 (12+log(O/H)~7.2). With these observations, dust is detected at 870micron (ALMA Band 7), but 87% of the flux in this band is due to free-free emission from the starburst. We have compiled a spectral energy distribution (SED) of SBS0335-052 that spans almost 6 orders of magnitude in wavelength and fit it with a spherical dust shell heated by a single-age stellar population; the best-fit model gives a dust mass of (3.8+/-0…
We use Atacama Large Millimeter/submillimeter Array (ALMA) observations of H30$α$ (231.90 GHz) emission from the low metallicity dwarf galaxy NGC 5253 to measure the star formation rate (SFR) within the galaxy and to test the reliability of SFRs derived from other commonly-used metrics. The H30$α$ emission, which originates mainly from the central starburst, yields a photoionizing photon production rate of (1.9$\pm$0.3)$\times$10$^{52}$ s$^{-1}$ and an SFR of 0.087$\pm$0.013 M$_\odot$ yr$^{-1}$ based on conversions that account for the low metallicity of the galaxy and for stellar rotation. Am…
We present ALMA observations of the 2M1207 system, a young binary made of a brown dwarf with a planetary-mass companion at a projected separation of about 40 au. We detect emission from dust continuum at 0.89 mm and from the $J = 3 - 2$ rotational transition of CO from a very compact disk around the young brown dwarf. The small radius found for this brown dwarf disk may be due to truncation from the tidal interaction with the planetary-mass companion. Under the assumption of optically thin dust emission, we estimated a dust mass of 0.1 $M_{\oplus}$ for the 2M1207A disk, and a 3$σ$ upper limit …
We present ALMA observations of the [CII] line and far-infrared (FIR) continuum of a normally star-forming galaxy in the reionization epoch, the z=6.96 Ly-alpha emitter (LAE) IOK-1. Probing to sensitivities of sigma_line = 240 micro-Jy/beam (40 km/s channel) and sigma_cont = 21 micro-Jy/beam, we found the galaxy undetected in both [CII] and continuum. Comparison of UV - FIR spectral energy distribution (SED) of IOK-1, including our ALMA limit, with those of several types of local galaxies (including the effects of the cosmic microwave background, CMB, on the FIR continuum) suggests that IOK-1 …
We present the highest resolution (1") $^{12}$CO(1-0) observations of molecular gas in the dwarf starburst galaxy NGC 625, to date, obtained with ALMA. Molecular gas is distributed in discrete clouds within an area of $0.4$ kpc$^2$ and does not have well-ordered large-scale motions. We measure a total molecular mass in NGC 625 of $5.3\times 10^6 M_\odot$, assuming a Milky Way CO-to-H$_2$ conversion factor. We use the CPROPS package to identify molecular clouds and measure their properties. The 19 resolved CO clouds have a median radius of 20 pc, a median line width 2.5 km s$^{-1}$, and a media…
We present observations of CO(3-2) and $^{13}$CO(3-2) emission near the supernebula in the dwarf galaxy NGC 5253, which contains one of the best examples of a potential globular cluster in formation. The 0.3" resolution images reveal an unusual molecular cloud, "Cloud D1", coincident with the radio-infrared supernebula. The ~6-pc diameter cloud has a linewidth, $Δ$ v = 21.7 km/s, that reflects only the gravitational potential of the star cluster residing within it. The corresponding virial mass is 2.5 x 10$^5$ M$_\odot$. The cluster appears to have a top-heavy initial mass function, with $M_{l…
We present the first results of the ALMA Fornax Cluster Survey (AlFoCS): a complete ALMA survey of all members of the Fornax galaxy cluster that were detected in HI or in the far infrared with Herschel. The sample consists of a wide variety of galaxy types, ranging from giant ellipticals to spiral galaxies and dwarfs, located in all (projected) areas of the cluster. It spans a mass range of 10^(~8.5 - 11) M_Sun. The CO(1-0) line was targeted as a tracer for the cold molecular gas, along with the associated 3 mm continuum. CO was detected in 15 of the 30 galaxies observed. All 8 detected galaxi…
We investigate the molecular gas in, and star-formation properties of, the host galaxy (CGCG 137-068) of a mysterious transient, AT2018cow, at kpc and larger scales, using archival band-3 data from the Atacama Large Millimeter/submillimeter Array (ALMA). AT2018cow is the nearest Fast-Evolving Luminous Transient (FELT), and this is the very first study unveiling molecular-gas properties of FELTs. The achieved rms and beam size are 0.21 mJy beam$^{-1}$ at a velocity resolution of $40$ km s$^{-1}$ and $3".66\times2".71$ ($1.1~{\rm kpc} \times 0.8~{\rm kpc}$), respectively. CO($J$=1-0) emission is…
Metals are thought to have profound effects on the internal structures of molecular clouds in which stars are born. The absence of metals is expected to prevent gas from efficient cooling and fragmentation in theory. However, this effect has not yet been observed at low metallicity environments, such as in the early Universe and local dwarf galaxies, because of the lack of high spatial resolution maps of gas. We carried out ALMA observations of the carbon monoxide (CO) J=2-1 emission line at 1.4-parsec resolutions of a molecular cloud in DDO 70 at 7% solar metallicity, the most metal-poor gala…
We present ALMA cycle 0 observations of the molecular gas and dust in the IR-bright mid-stage merger VV114 obtained at 160 - 800 pc resolution. The main aim of this study is to investigate the distribution and kinematics of the cold/warm gas and to quantify the spatial variation of the excitation conditions across the two merging disks. The data contain 10 molecular lines, including the first detection of extranuclear CH3OH emission in interacting galaxies, as well as continuum emission. We map the 12CO(3-2)/12CO(1-0) and the 12CO(1-0)/13CO(1-0) line ratio at 800 pc resolution (in the units of…
We conduct a $^{12}$C$^{16}$O($J$=1-0) (hereafter CO) mapping survey of 64 galaxies in the Fornax cluster using the ALMA Morita array in cycle 5. CO emission is detected from 23 out of the 64 galaxies. Our sample includes dwarf, spiral and elliptical galaxies with stellar masses of $M_{\rm star}\sim10^{6.3-11.6}$~M$_\odot$. The achieved beam size and sensitivity are $15''\times8''$ and $\sim12$~mJy~beam$^{-1}$ at the velocity resolution of $\sim10$~km~s$^{-1}$, respectively. We study the cold-gas (molecular- and atomic-gas) properties of 38 subsamples with $M_{\rm star}>10^9$~M$_\odot$ combine…
We use ALMA to detect and image CO (1-0) emission from Minkowski's Object, a dwarf galaxy that is interacting with a radio jet from a nearby elliptical galaxy. These observations are the first to detect molecular gas in Minkowski's Object. We estimate the range in the mass of molecular gas in Minkowski's Object assuming two different values of the ratio of the molecular gas mass to the CO luminosity, $α_{\rm CO}$. For the Milky Way value of $α_{\rm CO}=4.6~M_{\odot}{\rm (K~km~s^{-1}~pc^2)^{-1}}$ we obtain a molecular gas mass of $M_{\rm H_2} =3.0 \times 10^7~M_{\odot}$, 6% of the HI gas mass. …
Henize 2-10 is a blue dwarf galaxy with intense star formation and one the most intriguing question about it is whether or not it hosts an accretingmassive black hole. We use H and K-band integral field spectra of the inner 130 pc$\times$130 pc of He 2-10 to investigate the emission and kinematics of the gas at unprecedented spatial resolution. The observations were done using the Gemini Near-Infrared Integral Field Spectrograph (NIFS) operating with the ALTAIR adaptive optics module and the resulting spatial resolutions are 6.5 pc and 8.6 pc in the K and H bands, respectively. Most of the lin…
We present high angular resolution ($\sim$0.94$"$) $^{12}$CO(1-0) Atacama Large Millimeter/Submillimeter Array (ALMA) observations obtained during the 2014 long baseline campaign from the eruptive bipolar flow from the multiple XZ Tau stellar system discovered by the Hubble Space Telescope (HST). These observations reveal, for the first time, the kinematics of the molecular flow. The kinematics of the different ejections close to XZ Tau reveal a rotating and expanding structure with a southeast-northwest velocity gradient. The youngest eruptive bubbles unveiled in the optical HST images are in…
We present new [O III] 88 ${\rm μ}$m observations of five bright $z \sim 7$ Lyman-break galaxies spectroscopically confirmed by ALMA through the [C II] 158 ${\rm μ}$m line, unlike recent [O III] detections where Lyman-${\rm α}$ was used. This nearly doubles the sample of Epoch of Reionisation galaxies with robust ($5 σ$) detections of [C II] and [O III]. We perform a multi-wavelength comparison with new deep HST images of the rest-frame UV, whose compact morphology aligns well with [O III] tracing ionised gas. By contrast, we find more spatially extended [C II] emission likely produced in neut…
Extreme emission-line galaxies (EELGs) at redshift z=1-2 provide a unique view of metal-poor, starburst sources that are the likely drivers of the cosmic reionization at z$\geq6$. However, the molecular gas reservoirs of EELGs - the fuel for their intense star-formation - remain beyond the reach of current facilities. We present ALMA [CII] and PdBI CO(2-1) observations of a z=1.8, strongly lensed EELG SL2S 0217, a bright Lyman-$α$ emitter with a metallicity 0.05 $Z_\odot$. We obtain a tentative (3-4$σ$) detection of the [CII] line and set an upper limit on the [CII]/SFR ratio of $\leq1\times10…
We present Atacama Large Millimeter/submillimeter Array observations of CO lines and dust continuum emission of the source RCSGA 032727--132609, a young $z=1.7$ low-metallicity starburst galaxy. The CO(3-2) and CO(6-5) lines, and continuum at rest-frame $450\,μm$ are detected and show a resolved structure in the image plane. We use the corresponding lensing model to obtain a source plane reconstruction of the detected emissions revealing intrinsic flux density of $S_{450\,μm}=23.5_{-8.1}^{+26.8}$ $μ$Jy and intrinsic CO luminosities $L'_{\rm CO(3-2)}=2.90_{-0.23}^{+0.21}\times10^{8}$ ${\rm K\,k…
NGC 4395 is a dwarf galaxy at a distance of about 4.3 Mpc (scale: ~0.021 pc mas$^{-1}$). It hosts an intermediate-mass black hole (IMBH) with a mass between ~10$^4$ and ~10$^5$ solar masses. The early radio observations of NGC 4395 with the very long baseline interferometry (VLBI) network, High Sensitivity Array (HSA), at 1.4 GHz in 2005 showed that its nucleus has a sub-mJy outflow-like feature (E) extending over 15 mas. To probe the possibility of the feature E as a continuous jet with a base physically coupled with the accretion disc, we performed deep VLBI observations with the European VL…
Cool evolved stars are known to be significant contributors to the enrichment of the interstellar medium through their dense and dusty stellar winds. High resolution observations of these outflows have shown them to possess high degrees of morphological complexity. We observed the asymptotic giant branch (AGB) star EP Aquarii with ALMA in band 6 and VLT/SPHERE/ZIMPOL in four filters the visible. Both instruments had an angular resolution of 0.025''. These are follow-up observations to the lower-resolution 2016 ALMA analysis of EP Aquarii, which revealed that its wind possesses a nearly face-on…
We present the ALMA survey of CO(2-1) emission from the 1/5 solar metallicity, Local Group dwarf galaxy NGC 6822. We achieve high (0.9 arcsec ~ 2 pc) spatial resolution while covering large area: four 250 pc x 250 pc regions that encompass ~2/3 of NGC 6822's star formation. In these regions, we resolve ~150 compact CO clumps that have small radii (~2-3 pc), narrow line width (~1 km/s), and low filling factor across the galaxy. This is consistent with other recent studies of low metallicity galaxies, but here shown with a 15 times larger sample. At parsec scales, CO emission correlates with 8 m…
We have mapped 12CO J=3-2 and other molecular lines from the "water-fountain" bipolar pre-planetary nebula (PPN) IRAS 16342-3814 with ~0."35 resolution using ALMA. We find (i) two very high-speed knotty, jet-like molecular outflows, (ii) a central high-density (> few x 10^6 cm^{-3}), expanding torus of diameter 1300 AU, and (iii) the circumstellar envelope of the progenitor AGB, generated by a sudden, very large increase in the mass-loss rate to >3.5 x 10^{-4} Msun/yr in the past ~455 yr. Strong continuum emission at 0.89 mm from a central source (690 mJy), if due to thermally-emitting dust, i…
We present sensitive observations carried out with the Atacama Large Millimeter/Submillimeter Array (ALMA) of the dusty debris disk HD 95086. These observations were made in bands 6 (223 GHz) and 7 (338 GHz) with an angular resolution of about 1$''$ which allowed us to resolve well the debris disk with a deconvolved size of 7.0$''$ $\times$ 6.0$''$ and with an inner depression of about 2$''$. We do not detect emission from the star itself and the possible inner dusty belt. We also do not detect CO (J=2-1) and (J=3-2) emission, excluding the possibility of an evolved gaseous primordial disk as …
