Wide field CO J = 3->2 mapping of the Serpens Cloud Core

Context. Outflows provide indirect means to get an insight on diverse star formation associated phenomena. On scales of individual protostellar cores, outflows combined with intrinsic core properties can be used to study the mass accretion/ejection process of heavily embedded protostellar sources. Methods. An area comprising 460"x230" of the Serpens cloud core has been mapped in 12 CO J = 3\to 2 with the HARP-B heterodyne array at the James Clerk Maxwell Telescope; J = 3\to 2 observations are more sensitive tracers of hot outflow gas than lower J CO transitions; combined with the high sensitivity of the HARP-B receptors outflows are sharply outlined, enabling their association with individual protostellar cores. Results. Most of ~20 observed outflows are found to be associated with known protostellar sources in bipolar or unipolar configurations. All but two outflow/core pairs in our sample tend to have a projected orientation spanning roughly NW-SE. The overall momentum driven by outflows in Serpens lies between 3.2 and 5.1 x 10^(-1) M\odot km s^(-1), the kinetic energy from 4.3 to 6.7 x 10^(43) erg and momentum flux is between 2.8 and 4.4 x 10^(-4) M\odot km s^(-1) yr^(-1). Bolometric luminosities of protostellar cores based on Spitzer photometry are found up to an order of magnitude lower than previous estimations derived with IRAS/ISO data. Conclusions. We confirm the validity of the existing correlations between the momentum flux and bolometric luminosity of Class I sources for the homogenous sample of Serpens, though we suggest that they should be revised by a shift to lower luminosities. All protostars classified as Class 0 sources stand well above the known Class I correlations, indicating a decline in momentum flux between the two classes.Comment: 15 pages, 10 figures, accepted for publication in A&

Atomic jet from SMM1 (FIRS1) in Serpens uncovers non-coeval binary companion

We report on the detection of an atomic jet associated with the protostellar source SMM1 (FIRS1) in Serpens. The jet is revealed in [FeII] and [NeII] line maps observed with Spitzer/IRS, and further confirmed in HiRes IRAC and MIPS images. It is traced very close to SMM1 and peaks at ~5 arcsec" from the source at a position angle of $\sim 125 degrees. In contrast, molecular hydrogen emission becomes prominent at distances > 5" from the protostar and extends at a position angle of 160 degrees. The morphological differences suggest that the atomic emission arises from a companion source, lying in the foreground of the envelope surrounding the embedded protostar SMM1. In addition the molecular and atomic Spitzer maps disentangle the large scale CO (3-2) emission observed in the region into two distinct bipolar outflows, giving further support to a proto-binary source setup. Analysis at the peaks of the [FeII] jet show that emission arises from warm and dense gas (T ~1000 K, n(electron) 10^5 - 10^6 cm^-3). The mass flux of the jet derived independently for the [FeII] and [NeII] lines is 10^7 M(sun)/yr, pointing to a more evolved Class~I/II protostar as the driving source. All existing evidence converge to the conclusion that SMM1 is a non-coeval proto-binary source.Comment: 10 pages, 7 figures, 1 table. Accepted for publication in Astronomy \& Astrophysic

Οι φορείς της μουσικής εκπαίδευσης στο ιταλικό μπαρόκ. Οι παραδοσιακές πρακτικές και οι νέοι θεσμοί: τα βενετικά ospedali και τα ναπολιτάνικα conservatorii.

Γενέτειρα του εικαστικού και μουσικού μπαρόκ, η Ιταλία αποτέλεσε το εκκολαπτήριο των εμβληματικών του μπαρόκ μουσικών ειδών και μορφών, συνθετικών πρακτικών, φωνητικών, οργανικών και ορχηστρικών ιδιωμάτων, τα οποία σύντομα θα μεταλαμπαδευτούν σε ολόκληρη τη Δ. Ευρώπη. Η Ιταλία δεν εξήγαγε μόνον μουσική, ιδέες και πρακτικές, αλλά παρήγαγε μέγα πλήθος συνθετών και εκτελεστών που θα διαπρέψουν στις ευρωπαϊκές αυλές. Η οργασμική ανάπτυξη της μουσικής στην Ιταλία του μπαρόκ υπήρξε απότοκο πληθώρας αλληλεξαρτώμενων παραγόντων, μεταξύ των οποίων και η ανάπτυξη της μουσικής εκπαίδευσης, η οποία παρότι διατηρεί πλείστα τα χαρακτηριστικά του παρελθόντος, εμφανίζει και άλλα, καινοφανή, καινοτόμα και ιδιωματικά. Στην παρούσα εργασία αποπειρώμεθα τη σκιαγράφηση των εκφάνσεων της μουσικής εκπαίδευσης στο ιταλικό μπαρόκ, παλαιών και νέων, δίνοντας έμφαση στους καινοφανείς θεσμούς των βενετικών ospedali και ναπολιτάνικων κονσερβατορίων. Προκαταρκτικώς, επιχειρούμε μία ανίχνευση των πολυαρίθμων συμπλεκομένων κοινωνικών, οικονομικών και πολιτικών παραμέτρων και των διανοητικών στάσεων, οι οποίες επηρέασαν τις εξελίξεις στη μουσική εκπαίδευση στο ιταλικό μπαρόκ. Στη συνέχεια, στο κυρίως μέρος της εργασίας, πραγματευόμαστε τους φορείς της μουσικής εκπαίδευσης στο ιταλικό μπαρόκ: αφενός, τους κατά παράδοσιν θεσμοθετημένους ή άτυπους φορείς και τις συνήθεις εκπαιδευτικές πρακτικές, αφετέρου την ανάδυση, επίρρωση και πρωτοφανή επιτυχία και διεθνή ακτινοβολία καινοφανών μουσικών εκπαιδευτικών θεσμών, οι οποίοι εδράσθηκαν σε ταπεινά προνοιακά ιδρύματα (ορφανοτροφεία, πτωχοκομεία, άσυλα) στη Βενετία και τη Νάπολη. Το φαινόμενο των βενετικών ospedali και των ναπολιτάνικων conservatorii επιχειρούμε να φωτίσουμε πολύπλευρα, παρουσιάζοντας τις διάφορες πτυχές του πλαισίου ανάπτυξής τους και των δραστηριοτήτων τους κατά τον 17ο και 18ο αιώνα.Italy, the birthplace of the artistic and musical Baroque movement, served as incubator for the most significant music genres and forms, compositional techniques, as well as vocal, instrumental and orchestral idioms of the Baroque style, which would eventually spread out throughout Western Europe. Serving not only as an exporter of the Baroque music, style and idea, Italy also produced a great number of composers and performers who would thrive in the European courts. This orgasmic growth of the musical scene in Italy during the Baroque period, is attributed to various interrelated features of the time, such as the evolution of musical education, which adopts additional, innovative elements, albeit maintaining numerous characteristics of the past. This essay attempts to outline the former and neoteric aspects of musical education in the Italian Baroque era, whilst emphasizing on the unprecedented institutions of the Venetian Ospedali and the Neapolitan Conservatorii. At first the author traces the various parameters of the socio – economical and political background as well as the intellectual notions of this particlular period, which have affected the development of musical training at the time. Towards the main part of the essay, the reader is presented to the various establishments of musical education in the Italian Baroque period; on one hand the traditional institutional forms and practices, either official or informal and on the other hand the emerging and unprecedented success and international acclaim of new educational foundations which evolved in the grounds of humble welfare institutions (orphanages, asylums and houses of the poor) in Venice and Naples. The author aims to illuminate the phenomena of the Venetian Ospedali and the Neapolitan Conservatorii, by presenting the various aspects of the framework of their development during the 17th and 18th century

A 22 Degree Tidal Tail for Palomar 5

Using Data Release 4 of the Sloan Digital Sky Survey, we have applied an optimal contrast, matched filter technique to trace the trailing tidal tail of the globular cluster Palomar 5 to a distance of 18.5 degrees from the center of the cluster. This more than doubles the total known length of the tail to some 22 degrees on the sky. Based on a simple model of the Galaxy, we find that the stream's orientation on the sky is consistent at the 1.7 sigma level with existing proper motion measurements. We find that a spherical Galactic halo is adequate to model the stream over its currently known length, and we are able to place new constraints on the current space motion of the cluster.Comment: 10 pages, 3 figures, accepted for publication in ApJ Letter

Herschel spectral-line mapping of the HH211 protostellar system

(Abridged) Mid- and far-infrared observations of the environment around embedded protostars reveal a plethora of high excitation molecular and atomic emission lines. In this work we present spectro-imaging observations of the HH211 system with Herschel/PACS that record emission from major molecular (CO, H2O and OH) and atomic coolants (e.g. [OI]). Molecular lines are mainly exited at the terminal bowshocks of the outflow and around the position of the protostar. All lines show maxima at the southeast bowshock with the exception of water emission that peaks around the central source. Excitation analysis in all positions shows that CO and H$_2$O are mainly thermally excited at T~ 350 K and 90 K respectively, with the CO showing a second temperature component at 750 K towards the southeast peak. Excitation analysis breaks down in the case of OH, indicating that the molecule is non-thermally excited. Comparisons between the CO and H2 column densities suggest that the CO abundance value in shocks can be up to an order of magnitude lower than the canonical value of 10$^{-4}$. The water ortho-to-para ratio around the protostar is only 0.65, indicating low-temperature water ice formation followed by non-destructive photodesorption from the dust grains. Therefore the low ortho-to-para ratio in water that can be interpreted in terms of formation from a primordial gas reservoir in the protostellar envelope. The two-sided total atomic mass flux estimated from the [OI] jet sums to 1.65$\times 10^{-6}$ M$_{\odot}$ yr$^{-1}$, a value that is very close to the mass flux previously estimated for the SiO jet and the H$_2$ outflow. These comparisons render HH211 the first embedded system where an atomic jet is demonstrably shown to possess enough momentum to drive the observed molecular jets and large scale outflows.Comment: 10 pages, 6 figures, Accepted for publication in Astronomy & Astrophysic

Spitzer spectral line mapping of the HH211 outflow

Aims: We employ archival Spitzer slit-scan observations of the HH211 outflow in order to investigate its warm gas content, assess the jet mass flux in the form of H2 and probe for the existence of an embedded atomic jet. Methods: Detected molecular and atomic lines are interpreted by means of emission line diagnostics and an existing grid of molecular shock models. The physical properties of the warm gas are compared against other molecular jet tracers and to the results of a similar study towards the L1448-C outflow. Results: We have detected and mapped the v=0-0 S(0) - S(7) H2 lines and fine-structure lines of S, Fe+, and Si+. H2 is detected down to 5" from the source and is characterized by a "cool" T~300K and a "warm" T~1000 K component, with an extinction Av ~ 8 mag. The amount of cool H2 towards the jet agrees with that estimated from CO assuming fully molecular gas. The warm component is well fitted by C-type shocks with a low beam filling factor ~ 0.01-0.04 and a mass-flux similar to the cool H2. The fine-structure line emission arises from dense gas with ionization fraction ~0.5 - 5 x 10e-3, suggestive of dissociative shocks. Line ratios to sulfur indicate that iron and silicon are depleted compared to solar abundances by a factor ~10-50. Conclusions: Spitzer spectral mapping observations reveal for the first time a cool H$_2$ component towards the CO jet of HH211 consistent with the CO material being fully molecular and warm at ~ 300 K. The maps also reveal for the first time the existence of an embedded atomic jet in the HH211 outflow that can be traced down to the central source position. Its significant iron and silicon depletion excludes an origin from within the dust sublimation zone around the protostar. The momentum-flux seems insufficient to entrain the CO jet, although current uncertainties on jet speed and shock conditions are too large for a definite conclusion.Comment: 13 pages, 10 figures, accepted for publication in A&

Warm gas towards young stellar objects in Corona Australis - Herschel/PACS observations from the DIGIT key programme

The effects of external irradiation on the chemistry and physics in the protostellar envelope around low-mass young stellar objects are poorly understood. The Corona Australis star-forming region contains the R CrA dark cloud, comprising several low-mass protostellar cores irradiated by an intermediate-mass young star. We study the effects on the warm gas and dust in a group of low-mass young stellar objects from the irradiation by the young luminous Herbig Be star R CrA. Herschel/PACS far-infrared datacubes of two low-mass star-forming regions in the R CrA dark cloud are presented. The distribution of CO, OH, H2O, [C II], [O I], and continuum emission is investigated. We have developed a deconvolution algorithm which we use to deconvolve the maps, separating the point-source emission from the extended emission. We also construct rotational diagrams of the molecular species. By deconvolution of the Herschel data, we find large-scale (several thousand AU) dust continuum and spectral line emission not associated with the point sources. Similar rotational temperatures are found for the warm CO ($282\pm4$ K), hot CO ($890\pm84$ K), OH ($79\pm4$ K), and H2O ($197\pm7$ K) emission, respectively, in the point sources and the extended emission. The rotational temperatures are also similar to what is found in other more isolated cores. The extended dust continuum emission is found in two ridges similar in extent and temperature to molecular mm emission, indicative of external heating from the Herbig Be star R CrA. Our results show that a nearby luminous star does not increase the molecular excitation temperatures in the warm gas around a young stellar object (YSO). However, the emission from photodissociation products of H2O, such as OH and O, is enhanced in the warm gas associated with these protostars and their surroundings compared to similar objects not suffering from external irradiation.Comment: 37 pages, accepted for publication in A&

Infrared and sub-mm observations of outbursting young stars with Herschel and Spitzer

Episodic accretion plays an important role in the evolution of young stars. Although it has been under investigation for a long time, the origin of such episodic accretion events is not yet understood. We investigate the dust and gas emission of a sample of young outbursting sources in the infrared to get a better understanding of their properties and circumstellar material, and we use the results in a further work to model the objects. We used Herschel data, from our PI program of 12 objects and complemented with archival observations to obtain the spectral energy distributions (SEDs) and spectra of our targets. We report here the main characteristics of our sample, focussing on the SED properties and on the gas emission lines detected in the PACS and SPIRE spectra. The SEDs of our sample show the diversity of the outbursting sources, with several targets showing strong emission in the far-infrared from the embedded objects. Most of our targets reside in a complex environment, which we discuss in detail. We detected several atomic and molecular lines, in particular rotational CO emission from several transitions from J=38-37 to J=4-3. We constructed rotational diagrams for the CO lines, and derived in three domains of assumed local thermodynamic equilibrium (LTE) temperatures and column densities, ranging mainly between 0-100 K and 400-500K. We confirm correlation in our sample between intense CO $J=16-15$ emission and the column density of the warm domain of CO, N(warm). We notice a strong increase in luminosity of HH 381 IRS and a weaker increase for PP 13 S, which shows the beginning of an outburst.Comment: 23 pages, 17 figures, A&A accepte

L1448-MM Observations by the Herschel Key Program, "Dust, Ice, and Gas in Time" (DIGIT)

We present Herschel/Photodetector Array Camera and Spectrometer (PACS) observations of L1448-MM, a Class 0 protostar with a prominent outflow. Numerous emission lines are detected at 55 1000 K) environment, indicative of a shock origin. For OH, IR-pumping processes play an important role in the level population. The molecular emission in L1448-MM is better explained with a C-shock model, but the atomic emission of PACS [O I] and Spitzer/Infrared Spectrograph [Si II] emission is not consistent with C-shocks, suggesting multiple shocks in this region. Water is the major line coolant of L1448-MM in the PACS wavelength range, and the best-fit LVG models predict that H2O and CO emit (50%-80%) of their line luminosity in the PACS wavelength range.Herschel Open Time Key Project ProgramNASAJet Propulsion Laboratory, California Institute of TechnologyBasic Science Research Program through the National Research Foundation of Korea (NRF)Ministry of Education of the Korean government NRF-2010-0008704, NRF-2012R1A1A2044689Core Research Program of NRFMinistry of Science, ICTFuture Planning of the Korean government NRF-2011-0015816Korea Astronomy and Space Science InstituteKorean government (MEST)Astronom

Feedback of molecular outflows from protostars in NGC 1333 revealed by Herschel and Spitzer spectro-imaging observations

Context. Far infrared cooling of excited gas around protostars has been predominantly studied in the context of pointed observations. Large-scale spectral maps of star forming regions enable the simultaneous, comparative study of the gas excitation around an ensemble of sources at a common frame of reference, therefore, providing direct insights in the multitude of physical processes involved.Aims. We employ extended spectral-line maps to decipher the excitation, the kinematical, and dynamical processes in NGC 1333 as revealed by a number of different molecular and atomic lines, aiming to set a reference for the applicability and limitations of different tracers in constraining particular physical processes.Methods. We reconstructed line maps for H-2, CO, H2O, and [CI] using data obtained with the Spitzer infrared spectrograph and the Herschel HIFI and SPIRE instruments. We compared the morphological features revealed in the maps and derive the gas excitation conditions for regions of interest employing local thermodynamic equilibrium (LTE) and non-LTE methods. We also calculated the kinematical and dynamical properties for each outflow tracer in a consistent manner for all observed outflows driven by protostars in NGC 1333. We finally measured the water abundance in outflows with respect to carbon monoxide and molecular hydrogen.Results. CO and H-2 are highly excited around B-stars and, at lower, levels trace protostellar outflows. H2O emission is dominated by a moderately fast component associated with outflows. H2O also displays a weak, narrow-line component in the vicinity of B-stars associated to their ultraviolet (UV) field. This narrow component is also present in a few of outflows, indicating UV radiation generated in shocks. Intermediate J CO lines appear brightest at the locations traced by the narrow H2O component, indicating that beyond the dominating collisional processes, a secondary, radiative excitation component can also be active. The morphology, kinematics, excitation, and abundance variations of water are consistent with its excitation and partial dissociation in shocks. Water abundance ranges between 5 x 10(-7) and similar to 10(-5), with the lower values being more representative. Water is brightest and most abundant around IRAS 4A, which is consistent with the latter hosting a hot corino source. [CI] traces dense and warm gas in the envelopes surrounding protostars. Outflow mass flux is highest for CO and decreases by one and two orders of magnitude for H-2 and H2O, respectively.Conclusions. Large-scale spectral line maps can provide unique insights into the excitation of gas in star-forming regions. A comparative analysis of line excitation and morphologies at different locations allows us to decipher the dominant excitation conditions in each region in addition to isolating exceptional cases