Scientific Programme


Day 1, April 15 (afternoon)
12:00 Registration

The ALMA & Herschel Archives, Chair: Paola Andreani

13:00 Opening/Welcome
I will provide an overview of the ALMA observatory, including its present and future capabilities. I will describe the strengths and drawbacks of an interferometer, how to make the best use of the observatory capabilities and how ALMA attempts to mitigate some of the limitations of the interferometers. I will show a selection of science results from ALMA demonstrating the strengths and transformational science that the observatory is producing, trying to highlight the synergies with Herschel. [Full Presentation]
Leonardo Testi
We run through the ALMA Science portal, present the different types of data available and then concentrate on the Science Archive. We briefly describe the holdings, show the standard workflow and present the externally developed tool astroquery. [Full Presentation]
Felix Stoehr
This talk reviews the content of the ALMA science products and how they are generated (status ALMA Cycle 2). ALMA data are calibrated and imaged as part of the ALMA Quality Assurance (QA) which is organised in three levels 0, 1, and 2 covering different requirements based on each of which an observation can be rejected. If QA2 is passed, the project is delivered to the PI. The processing is performed semi-automatically with the help of CASA, the ALMA pipeline, the ALMA QA2 script generator, and other tools. Roughly 35 people are involved worldwide full-time. [Full Presentation]
Dirk Petry
I will briefly describe how European users can find information related to ALMA data (and not only) and how they can request and obtain face-to-face support to reduce their proprietary or Archival ALMA data. I will then present some statistics on publications making use of ALMA data.[Full Presentation]
Evanthia Hatziminaoglou
I will demonstrate how to extract from the ALMA archive the images and cubes of any target of choice, and how to display these. Then, if a user wishes to make new image products -- either continuum images or spectral lines cubes that were not contained within the archive package -- I will show what steps have to be taken to recreate a fully calibrated measurement set that is needed for imaging. The main CASA imaging tasks will be discussed briefly. [Full Presentation]
Martin Zwaan
14:50 Break
I will briefly introduce the Herschel mission, pointing out what Herschel has added in terms of observing phase space. I will provide an overview of actual Herschel observing, with numbers regarding different scientific fields and instrument usage. I will provide examples of the leap in observational results enabled by Herschel, emphasizing that the resulting data products are all publicly available. Snapshots of science will be used to illustrate science done, alluding to ALMA synergy, and I will provide information regarding Herschel publications statistics. [Full Presentation]
Göran Pilbratt
I will demonstrate how to query and get information of Herschel Observations and how to retrieve science products from the Herschel Science Archive (HSA)
using the HSA User Interface. I will briefly describe the different type of products available and explain the products generated at the several levels of processing per observation. [Full Presentation (pptx)]
Eva Verdugo
An overview of the status of the archival products is provided. This includes the status of their calibration and cross-calibration, a review of the satellite performance including pointing, and possible future improvements. Significant improvements in many product areas are continuing during the post-cryogen phase of the Herschel mission as detailed calibrations and deeper knowledge are put in place. Although continuing until the end of 2017, the vast majority of
the work has recently been put in place for the next archival reprocessing. [Full Presentation]
Anthony Marston
I will briefly describe the different data-mining tools which are available for the users community to explore the contents of the Herschel Science Archive. With the help of these tools users interested in the  scientific exploitation of Herschel data in combination with other facilities like ALMA should be able to answer questions like:
  i) Was my favourite astronomical source observed with Herschel?
 ii) To what extent has my research area been covered by any Herschel observing programme?
iii) What kind of added value information based on Herschel data is available on my favourite target/research area?
iv) Has this particular Herschel observation resulted in any refereed publication?
 v) What has been published on my favourite target/research area based on Herschel observations?
vi) How can I use Herschel data in combination with data taken by other facilities/observatories? [Full Presentation]
Pedro Garcia-Lario
We will make a very brief introduction to Herschel photometry with PACS and SPIRE. Some guidelines on the best practices to get the best photometry out of SPIRE images will be presented. Special emphasis will be put on some peculiarities of the Herschel data: maps with point source and extended source calibration, PSF/beam properties, colour corrections, confusion noise and blending. In this contribution we will also provide some guidelines on the best practice to extract the flux of spectral lines in data from the HIFI and the SPIRE spectrometers respectively. Emphasis will be put on the post-processing steps needed to be applied on the products served by the Herschel Science Archive, especially to take into account the potential semi-extended nature of the source. We take as an example the CO J=6-5 line as observed by both instruments in the AGB star IRC+10216. [Full Presentation Ivan Valtchanov] [Full Presentation David Teyssier]

Ivan Valtchanov
David Teyssier

17:10-18:00 Discussion
18:00 Reception  
Day 2, April 16

The ALMA & Herschel Archives

The PACS instrument of the Herschel Space Observatory observed ~10% of the sky in bands centred at 70/100 and 160 microns. Our goal is to create a homogenous point source catalogue extracted from the ~8,000 observations targeting a variety of extragalactic and Galactic environments. The PACS sensitivity and angular resolution at these wavelengths provides an excellent opportunity to discover objects of the cold Universe and the catalogue can be used as a potential target list for future ALMA observations. We present our findings from the feasibility phase including comparison of different source detection and photometric tools. We describe a method that we aim to use in the characterisation and quality check of the catalogued sources, including completeness, photometric accuracy and reliability. The first results of the test procedures will be also presented along with the description of our preliminary pipeline and catalogue entries. [Full Presentation]
Gabor Marton
Herschel-SPIRE created an excellent dataset thanks to its stability and sensitivity. We are building a homogeneous Point Source Catalog (SPSC) from all 6917 scan map observations centered at 250, 350, and 500 microns, covering ~11% of the sky. Although some source catalogs have already been produced, many obs. from small programs would never be analyzed for their full source content. Our team of experts estimates to extract approx. 3*10^6 reliable sources, using the best methods in a homogeneous way. The catalog can serve as a pathfinder for ALMA and similar facilities for many years to come. [Full Presentation]
Bernhard Schulz

Cosmology/High-redshift Universe; Chair Dieter Lutz

I will present some recent results that combine ALMA cycle 0/1 and Herschel SPIRE surveys of distant, sub-mm galaxies (SMGs). The ALMA and Herschel data allow us to investigate the properties of SMGs (redshift distribution, star formation rates, stellar masses and AGN activity). I will show that these distant (z~2.5) Ultra-luminous Infrared Galaxies have star-formation rates of ~300-1000 Msol/yr, substantial stellar masses (M*~6x10^10Mo) and cold molecular gas fractions of ~40% - which are many of the properties expected for the progenitors of today massive spheroids and elliptical galaxies. Indeed, accounting for the fading of the stellar populations, the space density of the descendent of SMGs are consistent with the entire population of local luminous ellipticals. Finally, I will show some recent results from ALMA cycle 1 and HST observations where we have obtained higher resolution (~0.1—0.3") maps of a sub-sample of bright SMGs, allowing us to compare the morphology of the star formation and stellar components. [Full Presentation]
Mark Swinbank (Invited)
COBE reveals the amount of the cosmic infrared background (CIB) is comparable to the optical one, but nearly 50% of the CIB has not been resolved even with recent ALMA studies. We thus explore the origin of the faint submm-mm emission ( < 0.1 mJy) which is hardly detected in previous both single-dish and interferometry studies by making full use of our latest ALMA cycle2 and archival cycle0-1 deep data. With > 100 pointings, which is largest to date, we find 87 faint ALMA sources in the range of flux density, 0.01 - 0.7 mJy, and almost fully (90 - 120%) resolve the CIB. By statistical counts-in-cells analysis, we investigate the clustering property of these faint ALMA sources, and find that these sources are probably the dust emissions from abundant star forming galaxies such as sBzKs and LBGs. We also conduct a search for optical/NIR counterparts of the faint ALMA sources, and confirm the statistical result on the individual sense. These results imply that the previously un-resolved 50% of the CIB is mainly contributed by well-known high-z star forming galaxies. [Full Presentation]
Seiji Fujimoto
Herschel deep extragalactic surveys (e.g. PEP, HerMES, GOODS-H) have delivered final data products to public archives. Starting from PEP science results, I will focus on the synergy between Herschel and ALMA in studying the SFR and the gas mass of distant galaxies. I will review the uncertainties and systematics of far-IR-only and sub-mm-only estimates, and how they compare to CO results. I will show that a combined ALMA+Herschel approach leads to <30% uncertainties. A dust-based measurement of the molecular gas mass function up to z~2, is within reach of ALMA over a GOODS-sized area. [Full Presentation]
Stefano Berta
11:00 Break  
The main feature of the Cosmic Star Formation History (CSFH) is a dramatic drop of the star formation (SF) activity, since z~1. We analyze the evolution of the SF activity in massive halos to understand if the very same process of assembly and growth of structures is one of the major drivers of the observed decline. Our results show that low mass groups provide a 60-80% contribution to the CSFH at z~1. Such contribution declines faster than the CSFH at z<0.3, where the overall SF activity is sustained by lower mass halos. More massive systems provide only a marginal contribution at any epoch. The large contribution of low mass groups at z~1 is due to a large fraction of very massive, highly star forming Main Sequence galaxies. Below z~1 a quenching process must take place in massive halos to cause the observed faster suppression of their SF activity. Starvation or the transition from cold to hot accretion would provide a quenching timescale of 1 Gyrs more consistent with the observations.
Paola Popesso
I will first present our results on the evolution of star-forming galaxies, in terms of dust attenuation and mode of star formation, up to z~3 using the deepest Herschel imaging in the CANDELS fields. In the second part of the talk, I will present first results of our completed ALMA program that will allow, for the first time in a mass complete sample at z~4, to push our studies into the early Universe by sampling in band 7 the FIR rest-frame close to the dust peak emission. [Full Presentation]
Maurilio Pannella
Dusty galaxies detected by Herschel, typically in large surveys like H-ATLAS and HerMES, are prime targets for ALMA observations, aiming to relate to dust content of a galaxy to its (molecular) gas content. Examples of ALMA projects with (small) samples of galaxies at low and high redshifts are discussed. [Full Presentation]
Eelco van Kampen
The contribution talk reports on the latest developments of our team's study of a gravitationally lensed system, HATLAS J142935.3-002836 (H1429-0028, selected in the Herschel-ATLAS field), making use of observations ranging from near-infrared and radio high-resolution imaging with Hubble Space Telescope (HST), Keck-AO, and Jansky Very Large Array (Calanog et al. 2014; Messias et al. 2014, M14), to spatially resolved spectroscopy with the Atacama Large (sub-)Millimetre Array (ALMA, M14) and HST (Timmons et al. 2015). The system comprises a foreground edge-on disk galaxy (at zsp = 0.218) and a lensed background galaxy at zsp = 1.027. The study so far points to a 1:3 merger in the background forming stars at a rate of 100+/-80 Msun/yr, with a total stellar mass of 1.1+/-0.4 x 10^11 Msun. The total gas-mass in the inter-stellar medium is estimated to be 4.6+/-1.7 x 10^10 Msun, where >70% is expected to be in a molecular-phase. [Full Presentation]
Hugo Messias
A number of strongly lensed sub-mm galaxies has been detected by both Herschel and the South Pole Telescope. These are expected to be dust-enshrouded starburst galaxies, detectable via continuum emission from the dust heated by star-forming regions. Combining the high resolution observations from ALMA with a flux boost provided by the lensing magnification, these high-z objects can be studied in unprecedented detail. We present the pixelated reconstruction and analysis of a strongly lensed sub-mm galaxy SDP.81 (z~3) from the ALMA Long Baseline Campaign observations. The continuum emission and CO emission lines are used to study the morphology and kinematic structure of the source. The source emission is reconstructed using a novel visibility-fitting technique with a pixelated source model, thus avoiding the inherent limits of previously-used parametric source models when reconstructing the high-quality interferometric data. The application of this method to strong lensing data from the current and future ALMA observations provides a powerful tool for detailed studies of high-z sources. These results represent the highest-resolution map of a sub-mm galaxy at this redshift so far. [Full Presentation]
Matus Rybak
13:00 Lunch  

Local Universe; Chair: Ivan Valtchanov

The combination of Herschel data with ALMA observations is a powerful tool for characterizing the physical conditions of the interstellar medium (ISM) in galaxies. Both for continuum emission from dust (and bremsstrahlung) and for spectroscopic transitions of molecules and far-infrared (FIR) fine-structure (FS) lines, Herschel and ALMA together provide a potentially 'lethal' synergy. This talk will present several examples of how this synergy has been and can be more fully exploited for the study of the ISM in nearby galaxies. Science cases include the characterization of galaxy dust content and properties; excitation conditions of molecular gas; feedback as traced by FIR FS and molecular transitions; and how such studies of nearby galaxies serve as benchmarks for interpreting observations at high redshift. [Full Presentation]
Leslie Hunt (Invited)
Using Herschel and ALMA archival data, we obtain new estimates of the relations between far-IR lines and total IR luminosity due to star-formation or AGN activity. We separate the AGN and SF contributions using a broad-band SED decomposition analysis. Moreover, with radiative transfer simulations of nearby (U)LIRGs, we derive the expected intensity of several far-IR emission lines for different values of the SFR and gas metallicity, simulating line profiles and gas spatial distribution. We extrapolate the local relations/simulations to high z to predict the expected number of line detections. [Full Presentation]
Carlotta Gruppioni
Herschel has revealed that mid- and high-J CO lines in nearby galaxies are emitted from warm gas, accounting for approximately 10% of the molecular mass, but the majority of the CO luminosity. We present a method for accurate measurements of CO line fluxes in galaxies observed by the Herschel FTS (exploring systematic effects) and model the emission using a 2-component fit with RADEX. Though the Herschel FTS can measure many lines, it lacks in spectral/spatial resolution; ALMA offers the opportunity for detailed follow-up on high-J lines such as CO J=6-5. We present the case study of Arp 220. [Full Presentation]
Julia Kamenetzky
15:20 Break  
We present Atacama Large Millimeter/submillimeter Array (ALMA) observations of 99.02 GHz free-free and H40alpha emission from the centre of the nearby starburst galaxy NGC 253. These data represent one of the earliest detections of recombination line emission from an extragalactic object by ALMA. We illustrate how these data can be used not only to measure the star formation rate within an extremely dusty environment but also to measure the electron temperature of the photoionized gas. We also discuss how star formation rate measurements based on prior radio and millimetre observations have varied by nearly a factor of 10 and why star formation rates based on our ALMA data should be more accurate. We conclude with an additional analysis in which we demonstrate that the dust opacities are ~3 dex higher than inferred from previous analyses of near-infrared data, which illustrates the benefits of using millimetre star formation tracers to study very dusty sources. [Full Presentation]
George Bendo
I will present spatially resolved maps of dust emission of the host galaxy of the closest known GRB 980425 at z = 0.0085 using high-resolution observations from Herschel, Atacama Pathfinder Experiment (APEX), Atacama Large Millimeter Array (ALMA) and Australia Telescope Compact Array (ATCA). The host is characterised by low dust content and a high fraction of UV-visible star formation, similar to other dwarf galaxies. These galaxies are abundant in the local universe, so it is not surprising to find a GRB in one of them, assuming the correspondence between the GRB rate and star formation. The WR region close to the GRB site contributes substantially to the host emission at the far-infrared, millimetre, and radio wavelengths, and this may be a consequence of its high gas density. If dense environments are also found close to the positions of other GRBs, then the ISM density should also be considered, along with metallicity, an important factor influencing whether a given stellar population can produce a GRB. [Full Presentation]
Michal Michalowski
Herschel observations have revealed that the submm slope of the dust emission can differ from one galaxy to another. In some nearby objects, we have detected a 870um excess emission compared to predictions obtained from Herschel data and standard dust models. To understand the origin of the excess, we modeled the local IR-to-submm SEDs and derived relative excess map at 870μm. These excesses do not show a clear dependence with the galactic radius or the star formation activity, even if peaks preferentially appear in the outskirts rather than in the center of the objects. The origin of the excess is still an open question. Our study was unfortunately limited by the resolutions of the current maps that prevent a mapping of the cold dust emission below kpc scales. ALMA observations are critical to investigate the origin of the submm continuum emission and probe the sites where the excess could be produced. Some scenarios to explain the excess require a spatial correlation of the cold dust continuum with the molecular reservoirs (very cold dust or grain coagulation scenario). With ALMA, we will be able to compare the continuum emission to the distribution of molecular gas. [Full Presentation]
Maud Galametz
16:40-17:30 Discussion  
19:00 Dinner  
Day 3, April 17

ISM/Star formation; Chair: Leonardo Testi

The Herschel Space Observatory has provided important constraints on the chemical and physical processes in the ISM, molecular clouds, and star/planet forming regions. In this talk I shall review Herschel findings, highlighting the crucial synergy with ALMA to complete and deepen our current understanding of the various phases in the process of star and planet formation. [Full Presentation]
Paola Caselli (Invited)
Infrared dark could, or IRDC, is a loosely defined and technically biased term for intrinsically dense and cold dusty/molecular clouds that harbor the earliest stages of star formation. Herschel key projects Hi-GAL and EPoS provide sensitive far-IR images covering all the key wavelengths in the SEDs of these 10-20 K clouds, allowing determination of temperature, luminosity, and mass for a large number of dense clumps within IRDCs. Sufficiently massive clumps collapse under self-gravity and fragment to spawn a cluster of stars that have a range of masses. So far, few IRDC clumps have been observed by ALMA. We investigate observationally the early stages of star-cluster formation in a massive filamentary IRDC G28.34+0.06 P1 using ALMA. Sensitive continuum data reveal further fragmentation in five dusty cores at a resolution of several 10^3 AU. Three cores are chemically more evolved as compared with the other two, although all of them are associated with collimated outflows. We observe a surprising lack of a distributed low-mass protostellar population in the clump, indicating that in a protocluster, low-mass stars form at a later stage after the birth of more massive protostars. [Full Presentation]
Ke Wang
Herschel SPIRE continuum and Effelsberg-100m line observations of TMC-1 revealed its density and velocity structure. The HIPE 12.1.0 data processing was followed by a level-1 stage subtraction of point sources. The resulted images are the best so far to derive the colour temperature and column density of ISM in TMC-1. A simultaneous use of high resolution and high S/N NH3 spectra and Herschel column density distribution allowed us to identify clumps. Deriving the physical parameters (mass, kinetic temperature, turbulent velocity) of the clumps 5 of those were found to be gravitationally bound.
Orsolya Fehér
Giant molecular clouds contain supersonic turbulent motions that may play an important role in star formation. Such turbulence, however, is expected to decay rapidly and create a low volume-filling factor, hot gas component in GMCs. Models of low velocity shocks indicate that mid-J CO lines (J = 6-5 and higher) should preferentially trace this shocked gas. We present Herschel observations of these mid-J CO lines towards a low mass star forming region and three IRDCs, and discuss potential follow up observations with ALMA to resolve individual shock fronts in these regions. [Full Presentation - PDF] [Full Presentation - Power Point]
Andy Pon
10:40 Break
The European missions Planck and Herschel gave us the possibility to identify the whole Galactic population of massive pre-star/pre-cluster forming clouds with an unbiased selection criteria and to establish in great detail their density and temperature structure through direct measurements of their thermal dust emission in the far-infrared and sub-mm wavelengths. Based on the Planck Early Cold Cores catalogue cold clouds were studied with Herschel data from the Herschel Open Time Key Project "Herschel infrared Galactic Plane Survey" at higher spatial resolution. Herschel PACS and SPIRE observations of the selected 50 Planck cold clumps allowed us to examine the structure and physical characteristics of the sources and their environment. The selected clouds have distances ranging from 0.5 kpc to 8 kpc, and masses from a few solar masses to 100000 solar masses. This unbiased sample allowed us to select the best candidate in the earliest stage of massive star formation and to observe it with ALMA to determine its physical properties, fragmentation and gas dynamics. [Full Presentation]
Sarolta Zahorecz
During its lifetime, Herschel observed young stellar objects (YSOs) belonging to different stellar associations at different ages. We can now take advantage of this observations to study the evolution of the gas phase in circumstellar discs. I will present a catalogue of more than 250 Herschel-PACS spectroscopic observations of O and H2O in different associations. The main output of the catalogue is an [OI] detection frequency at 63 microns that can be used to tackle the evolution of the disc atmospheric gas. Recent studies have shown that the origin of the [OI] line is uncertain, and both the disc and the jet can contribute. Furthermore, the detectability of the [OI] line seems to be influenced not only by the total gas mass, but also by the UV radiation field and the flaring geometry of the disc. Therefore, to derive reliable gas masses and gas-to-dust mass ratios we need to complement the Herschel observations with ALMA observations in the continuum and in some lines of interest, like CO lines. Using these ALMA observations we can derive reliable gas-to-dust ratios and better understand the evolution of the gas phase with age. [Full Presentation]
Pablo Riviere-Marichalar
Transitional disks are protoplanetary disks with gaps in their dust distribution, pointing to possible on-going planet formation in them. The Herschel Space Observatory has provided far IR observations for several of these disks, probing cold material in their outer regions. I will summarize our results from Bayesian modeling of five transitional disks in the Chamaeleon-I region, and what Herschel data adds to our previous knowledge of this sources. Finally, I will discuss some of the many opportunities that the unprecedented ALMA capabilities will bring to this exciting topic. [Full Presentation]

Alvaro Ribas-Gomez
Transition disks, broadly defined as protoplanetary disks with inner cavity holes/gaps, are the most suitable places to understand planet formation. In this talk I will present our ALMA Cycle-0 (Band-6) results about the transition disk Sz 91 discussed by Canovas at al. 2015 (in press). Using radiative transfer models to fit our observations and the SED (including Herschel/PACS/SPIRE data) we conclude that Sz 91 has, by far, the largest cavity (97 au) observed in a transition disk around a low mass star. The Herschel data allow us to constrain the inner structure of the cavity. We find that its innermost regions must be largely devoid of dust, although there must be some dust inside it to account for the 22\micron excess and the Herschel fluxes. Our ALMA data also indicates the presence of CO inside the cavity. The lack of detected binary companions, the accretion rate, and the cavity size and structure of Sz 91 are in excellent agreement with theoretical predictions of ongoing multiple planet formation. [Full Presentation - PDF]
Hector Canovas
Dust in debris disks is produced by colliding or evaporating planetesimals, which are remnants of the planet formation process. Warm dust disks, known by their emission at less than 24 microns, are rare (4% of FGK main sequence stars) and especially interesting because they trace material in the region likely to host terrestrial planets, where the dust has a very short dynamical lifetime. Statistical analyses of the source counts of excesses as found with the mid-IR Wide Field Infrared Survey Explorer (WISE) suggest that warm-dust candidates found for the Kepler transiting-planet host-star candidates can be explained by extragalactic or galactic background emission aligned by chance with the target stars. These statistical analyses do not exclude the possibility that a given WISE excess could be due to a transient dust population associated with the target. Here we report Herschel/PACS 100 and 160 micron follow-up observations of a sample of Kepler and non-Kepler transiting-planet candidates’ host stars, with candidate WISE warm debris disks, aimed at detecting a possible cold debris disk in any one of them and discuss potential future ALMA follow-up observations of these systems. [Full Presentation - PDF]
Bruno Merin
12:40 Lunch

Astrochemistry, evolved stars and solar system objects; Chair: Emmanuel Caux

ALMA is making a revolution in Astrophysics. The high angular resolution provided by this instrument will unveil the innermost zones of starforming regions, AGB, post-AGBs stars and extragalactic objects. While these images will give an unique view of the structure of the sources, the interpretation of the data will require complementary information such as high energy transitions of abundant species and of dust properties derived from submillimeter and far-IR observations. Herschel's archive is an unique database providing a complete spectral view of the emission of most relevant objects in our galaxy and of the molecular content of extragalactic objects.
Although the angular resolution of ALMA if much higher than that of Herschel, even in its most compact configuration, the energies involved in molecular transitions observed with Herschel in the THz domain make certain that the emitting region observed with Herschel's instruments will be in most cases similar to that of ALMA observations. Hence, the use of the Herschel's archive to complement ALMA observations will be an extremely powerful tool to derive the physical and chemical conditions of these, so far, invisible zones of the ISM. [Full Presentation]
Jose Cernicharo (Invited)
Herschel Space Observatory and ALMA interferometer are allowing us to study the innermost regions of the evolved stars with unprecedented precision and sensitivity. These regions are where the key processes that drive the mass ejection of these objects take place. While ALMA provides accurately maps the molecular structures, HIFI profiles provides fundamental information on the excitation of the molecular gas. We present the sub-arcsecond interferometric maps for metal-bearing transitions towards the prototypical C-rich evolved stars IRC+10216. The Al-bearing molecules seem to present a roughly spherical structure. On the contrary, the molecular transition from the salts NaCl and KCl reveal the presence of a circumstellar torus. The orientation and the kinematical and chemical characteristics of this torus, suggest that this torus is probably the remains of a planetary system around this evolved star. [Full Presentation]

Guillermo Quintana-Lacaci
Silicon bearing molecules (SiS, SiO, SiC and SiC2) are found towards the circumstellar envelope (CSE) of IRC+10216. These molecules are efficiently formed in gas phase, close to the stellar photosphere as a consequence of chemical processes enabled under thermodynamical equilibrium. These molecules are expected to condense onto the dust grains in the dust formation region due to their highly refractory nature. Hence, the study of these molecules is key for understanding the dust formation zone and the processes at work in that region. In this talk, we will present our latest results concerning the Si-bearing molecules towards IRC+10216, with ALMA band 6 (255-275 GHz) during the Cycle0. These observations allowed us to detect and characterize the brightness distribution of rotational lines of high-vibrational states of SiS, and also SiO and SiC2 lines in the ground vibrational state. We will also review the available information of these molecules from Herschel previous works and how both ALMA and Herschel complement to produce a better picture of the CSE of evolved stars, providing the spatial structure at high angular resolution and the detailed excitation conditions of the gas. [Full Presentation]
Luis Velilla Prieto
15:00 Break
The opening of unexplored spectral windows by the Herschel Space Telescope has allowed to observe many new molecules, mainly light hydrides, whose rotational spectrum lies at submillimeter wavelengths not accessible from ground. In the well known carbon-star envelope IRC+10216 it has been possible to detect emission lines of H2O, NH3, HF, HCl, and PH3 (the three latter detected for the first time) arising from the inner envelope. On the other hand, the unprecedented angular resolution that ALMA is starting to provide does also allow to probe the spatial distribution of molecules in the inner layers of IRC+10216. As an example, we have recently detected a peculiar emission distribution for CH3CN, consisting of a hollow shell of 2 arcsec radius. The Herschel and ALMA observations is thus providing a more complete picture of the chemical processes at work in the inner regions of IRC+10216’s envelope, in some cases confirming the expectations of chemical models (as occurs with the detection of HF and HCl) albeit in other cases providing unexpected results (as occurs with the detection of H2O and PH3 and with the spatial distribution of CH3CN). [Full Presentation]
Marcelino Agundez
Studies of abundant molecules in Orion KL using observations from three line surveys performed with the IRAM 30-m telescope (80-307 GHz), the HIFI instrument onboard the Herschel telescope (480−1906 GHz), and the ALMA interferometer (214-247 GHz) are required to understand the role of the different components observed inside this complex region and the particular chemistry found in each one. Molecules such as CS, OCS, CH3OH, CH3OCOH, CH3OCH3, CH3CN, CH3CH2CN, CH2CHCN, HC3N, SO, SO2 are detected in the three data set by many lines covering an unprecedented amount of transitions (so an unprecedented energy range). The combination of different set of data allow us to provide very constrained physical parameters of the cloud (source diameters of different components, density and temperature gradients, and an accurate kinematics of the different Orion’s components) as well as very constrained column densities for the studied species. Reliable physical and chemical parameters are provided by modelling the lines of the detected molecules using MADEX, which permit us to choose between LVG and LTE approximations depending on the physical conditions of the gas. [Full Presentation]
Belén Tercero
The nitrogen-dominated atmosphere of Titan exhibits a great diversity and complexity of molecules and high organic material abundances. In the framework of the Herschel guaranteed time key programme "Water and Related Chemistry in the Solar System" (Hartogh et al 2009), we conducted observations of the atmosphere of Titan with HIFI, PACS and SPIRE onboard Herschel (Rengel et al. 2014; Courtin et al. 2011, Moreno et al. 2011, 2012). Here we will review key results and discoveries on the atmosphere of Titan obtained with Herschel.
[Full Presentation]
Miriam Rengel
16:20-17:15 Discussion
17:15 End of the Workshop