bluuebunny/crossref_metadata_2025 huggingface dataset:
Matching Data: Analyzing the Chronological Use Sequence in the Iron Age Necropolis of the Staggered Turriform of Son Ferrer (Balearic Islands, Spain)
Authors: Trias Manuel Calvo , Rosselló Jaume García , Molina David Javaloyas , Santacreu Daniel Albero , Van Strydonck Mark
Published: July 2016

The Son Ferrer archaeological site presents a series of successive occupations spanning a long period of time. At the beginning of the Iron Age (∼850 BC), a staggered turriform structure was built for a ritual purpose over an artificial hypogeum that had already been used as a collective necropolis during the Early Bronze Age (∼1800–1500 BC). Later, in the post-Talayotic phase (Second Iron Age, 550–123 BC), the hypogeum was again reused as a collective burial place. The present work is focused on the chronological and functional analysis of this last phase, which began ∼500 BC and ended ∼180 BC with the saturation and sealing of the hypogeum. The excavation process revealed that significant removal of archaeological material has occurred as a result of complex funerary space management practices, which generated a secondary archaeological context. Given this situation, and in order to establish the different use phases of the post-Talayotic necropolis, a dual strategy of excavation and research was implemented. First, an extensive series of radiocarbon dates on human remains (18 dates) was obtained, which were later analyzed following Bayesian strategies. Second, a detailed spatial analysis was carried out, georeferencing the location of all the archaeological finds. This strategy allowed the reconstruction of the space management processes and movement patterns that took place in the burial space. Despite some initial difficulties, the combination of these research strategies embedded in a contextual analysis provided both material and chronological references that have contributed to define the various use phases of the hypogeum.
Radiocarbon Dating of the Necropolis of the Early Christian Site of Son Peretó (Mallorca, Balearic Islands)
Authors: Cau Miguel Á , Rullan Mateu Riera , Salas Magdalena , Van Strydonck Mark
Published: July 2016

Radiocarbon dates, obtained from different human bones found in several tombs of the site of Son Peretó, are presented and discussed together with the stratigraphical evidence and the study of the material culture. The calibrated dates show that the tombs were built earlier than the main phase of occupation of the West Sector, therefore belonging to a necropolis linked to the Christian building prior to the transformation of the area into a habitation nucleus. The necropolis is14C dated mainly to the 6th century AD. This is in good agreement with the chronology provided by ceramic materials.
New Data from Fortified Coastal Settlement of Cap de Forma, Mahon, Menorca (Balearic Islands)
Authors: Depalmas Anna
Published: July 2016

This article presents new radiometric data from archaeological layers of the inhabited structures adjacent to the cyclopean monument of Cap de Forma (Mahon, Menorca). The archaeological site is located on a narrow isthmus that links a 30-m-high coastal promontory to the mainland. It is next to an excellent natural harbor on the south coast of the island. The protohistorical complex consists of a cyclopean monument surrounded by a necropolis of rock-cut tombs (cuevas) that are dug into the cliff. The monument is an atypical example of Talayotic architecture. The excavations carried out since 1997 have discovered three living spaces. These lean against the southern wall of the cyclopean structure. The artifacts are almost all pan of a chronological horizon that corresponds to the beginning of the Talayotic period. This study uses radiometric data to help interpret the recent findings from the three living spaces that flank the wall of the central monument.
A New Perception of the Late Bronze Age Chronology in Belgium
Authors: Leclercq Walter
Published: July 2016

Since Marcel Edouard Mariën and his 1952 masterpiece synthesisOud-België van de eerste landbouwers tot de komst van Caesar, the beginning of the Late Bronze Age in Belgium has been situated around 1100 BC, corresponding to the phase Ha A2. The scarcity of artifacts from Reinecke's phases Bz C and Ha Al seemed to confirm this theory. Based on an axe's hoard (Maaseik, Belgium) and the presence of grooved ware, the potential existence of a Bz D/Ha Al phase has been suggested but certainly not certified. Currently, a large campaign of analyses on bones from several Late Bronze Age sites is shedding new light on Bronze Age chronology.
Radiocarbon Dating of the Neolithic Lakeside Settlement of Dispilio, Kastoria, Northern Greece
Authors: Facorellis Yorgos , Sofronidou Marina , Hourmouziadis Giorgos
Published: July 2016

Dispilio is the only excavated Neolithic lakeside settlement in Greece. Archaeological research provided evidence that the site was continuously used from the Early Neolithic (∼6000 BC) to the Late Chalcolithic period (∼1200 BC, Mycenaean period). During several archaeological campaigns, a portion of the settlement has been excavated that enabled a sufficient understanding of the architectural layout of homes, the building materials, and the organization of space, while the finds (fragments of pottery, stone and bone tools, anthropomorphic and zoomorphic clay figurines, miniature representations of objects also on clay, animal and fish bones, charred cereal grains, and other fruits) provided information on the everyday lives of the Neolithic inhabitants. A series of charcoal and wood samples, originating mostly from the Middle and Late Neolithic layers of the site, were radiocarbon dated and their dates range from ∼5470 to 4850 BC. The most unexpected of the finds, a wooden tablet from the lake bearing engraved symbols, was14C dated to 5260 ± 40 BC. In addition, clay tablets and pottery vessels engraved with similar symbols were also unearthed from layers dated to the same period. If this proves to be a primary source of written communication, the history of writing should be reconsidered and Neolithic societies should not be considered “societies without writing.”
Conventions for Reporting Radiocarbon Determinations
Authors: Millard Andrew R
Published: July 2016

Current conventions for reporting radiocarbon determinations do not cover the reporting of calibrated dates. This article proposes revised conventions that have been endorsed by many14C scientists. For every determination included in a scientific paper, the following should apply: (1) the laboratory measurement should be reported as a conventional radiocarbon age in14C yr BP or a fractionation-corrected fraction modern (F14C) value; (2) the laboratory code for the determination should be included; and (3) the sample material dated, the pretreatment method applied, and quality control measurements should be reported. In addition, for every calibrated determination or modeled date, the following should be reported: (4) the calibration curve and any reservoir offset used; (5) the software used for calibration, including version number, the options and/or models used, and wherever possible a citation of a published description of the software; and (6) the calibrated date given as a range (or ranges) with an associated probability on a clearly identifiable calendar timescale.
Carbon Exchanges between Bone Apatite and Fuels during Cremation: Impact on Radiocarbon Dates
Authors: Snoeck C , Brock F , Schulting R J
Published: July 2016

An important advance in the radiocarbon dating of archaeological material occurred in the late 1990s, with direct dating of cremated human remains. A crucial part of the argument was the demonstration that comparable results could be obtained from paired dates of charcoal and calcined bone from the same contexts. Recent studies, however, have noted the influence of carbon from the fuel sources, raising a question over the interpretation of the paired charcoal/bone dates. Here, fleshed modern animal joints were burned with “old” fuel of known age, providing experimental evidence under natural conditions, demonstrating a clear effect of the fuel source on the carbon isotopic composition of calcined bone. In most situations in which branchwood was used as fuel, dates on calcined bone should not show any significant offset, as the wood will be of a similar age to the cadaver. For cases in which old wood, coal, or peat are used as fuel, we expect an offset of some decades/centuries, potentially up to millennia. We observed, however, that the amount of14C intake from the fuel is extremely variable (from 39 to 95%). A strong correlation between age offset and δ13C values suggests that the latter might be useful in identifying large inputs from14C-depleted fuels. A level of caution is recommended when14C dating calcined bone in cases where fuels with an inbuilt age may have been used in the cremation process.
Textiles and Radiocarbon Dating
Authors: Hajdas Irka , Cristi Carlo , Bonani Georges , Maurer Mantana
Published: July 2016

Natural textiles provide suitable material for radiocarbon dating. Short-lived organic matter is usually involved and, if14C dating is applied to pieces that are stylistically well dated, a better understanding of14C dating of this type of material can be gained. This study presents some examples of dating that support the stylistic dates. Repeated analyses illustrate the robustness of the standard treatment applied to the textiles.
Wiggle-Match Dating of Tree-Ring Sequences from the Early Iron Age Defensive Settlement Motroninskoe Gorodishche in Mielniki (Central Ukraine)
Authors: Chochorowski Jan , Krąpiec Marek , Skoryj Sergej , Skrypkin Vadim
Published: July 2016

In 2002–2003, excavations were carried out within the early Iron Age fortified settlement of Motroninskoe Gorodishche in Mielniki (central Ukraine, obl. Cherkassy). The excavations revealed relics of a charred wooden structure in the core of the earth rampart, originally forming the outside fortification line of the settlement. Dendrochronological analysis of 20 charred pieces of the oakwood from the rampart demonstrated that they all represented a single construction phase. However, the chronology produced from them spanned only 62 yr, and the attempts of dating against the European oak standards were unsuccessful. For absolute dating, radiocarbon analysis was conducted on nine samples consisting of 4–8 tree rings, relatively dated and coming from selected timbers, of which dendrochronological sequences defined the above chronology. The wiggle-matching method allowed to determine the two most plausible periods tree cutting: 665–630 or 625–520 BC. The construction date of the rampart outlines the beginning of construction of the fortification system of one of the most heavily reinforced strongholds in eastern Europe raised by the local, settled population for defense against the nomadic Scythians invading from the steppe. Taking into account historic data and other dated artifacts, it may be assumed that the first period, 665–630 BC, would be more probable. This conclusion supports the historical process (crucial for eastern Europe) of migration of the Iranian Scythians from inside Asia and settling in areas around the Black Sea.
Dating Historical Contexts: Issues, Plant Material, and Methods to Date the Late Roman Site of Faragola, Apulia (SE Italy)
Authors: Caracuta V , Fiorentino G , Turchiano M , Volpe G
Published: July 2016

Charred plant materials found in archaeological contexts are usually considered the most reliable remains for radiocarbon dating. Usually, seeds and fruits are preferred to wood fragments because their short lifecycle reduces the range of uncertainty of the14C measurement. A selection of short-lived samples, mainly from barley and wheat, from the Late Roman site of Faragola (SE Italy) were14C dated; however, the14C dates obtained were not always consistent with the chronology provided by other archaeological evidence. A careful analysis of all the macrobotanical remains found in each of the dated contexts provides insight into the origin of the plant material, helping to distinguish betweenin situand non-in situmaterial. The14C dates are reconsidered in the context of findings and the kind of material selected for dating. Using the archaeological context, a Bayesian model was employed to reduce the range of the calibrated date and thereby refine the chronology of the site on an absolute basis.
Another Way of Early Pottery Distribution in Eastern Europe? Case Study of the Pezmog 4 Site, European Far Northeast
Authors: Karmanov Victor N , Zaretskaya Natalia E , Volokitin Alexander V
Published: July 2016

A case study of the Neolithic comb ceramic site Pezmog 4 of the Kama culture presents a situation when results of radiocarbon dating change long-existing concepts concerning the development of archaeological events. Until the early 2000s, the chronology of the Kama culture, distributed mainly in the Kama and Vychegda River basins, has been based on comparative-typological analysis. Estimates of the age of this culture changed from the 3rd millennium BC in the 1950s to the 1st half of the 4th millennium BC by the 1990s. Research concerning the Pezmog 4 site in the central Vychegda River basin in 1999–2002 has abruptly changed this chronological understanding. The data obtained put the age of the early stage of Kama culture within the time range 5750–5620 cal BC and allowed us to propose the existence of another way of early pottery distribution in the forest zone of eastern Europe at the beginning of the 6th millennium BC. This innovation probably penetrated from the trans-Ural region.
Variation in Radiocarbon Age Determinations from the Crystal River Archaeological Site, Florida
Authors: Cherkinsky Alexander , Pluckhahn Thomas J , Thompson Victor D
Published: July 2016

Archaeologists interested in radiocarbon dating shell midden sites express concern regarding the accuracy of shell dates and how such determinations should be interpreted. This article discusses the problem of dating shells from sites in the southeastern United States. New results are presented comparing shell, bone, and soil-charcoal age determinations from the Crystal River site, located along the west-central Gulf Coast of Florida. Crystal River is a large multimound site whose occupants engaged in long-distance exchange throughout eastern North America during the Woodland period (∼1000 BC to AD 1050). In the summer of 2012, test units were excavated in several contexts at the site, including both mounds and occupation areas. Samples were collected for14C dating, which were then processed at the University of Georgia Center for Applied Isotope Studies. This article focuses on samples from the stratified shell midden, from which it was hoped to construct a local correction for marine shell that could be used to date other contexts. The soil-charcoal and bone collagen from these samples have very similar ages (bone samples ranging from about 100 cal BC to cal AD 530 and soil-charcoal from cal AD 345 to 560); however, the shell samples collected from the same stratigraphic units are significantly older than the terrestrial dates (ranging from 1300 to 390 cal BC). The difference in calibrated ages between organic materials and the shells ranges between 560 to 1140 yr. This phenomenon cannot be explained solely by the marine reservoir effect. It appears that all the shell samples formed in mixed marine (∼50–60%) contexts, as indicated by the stable isotope ratios and the amount of atmospheric carbon remaining in the samples. The age of the shell samples cannot be used to date archaeological events as they are influenced not only by the marine reservoir effect, but also the local hardwater effect, which makes them significantly older.
Utilization of δ13C, δ15N, and δ34S Analyses to Understand 14C Dating Anomalies within a Late Viking Age Community in Northeast Iceland
Authors: Sayle Kerry L , Cook Gordon T , Ascough Philippa L , Gestsdóttir Hildur , Hamilton W Derek , McGovern Thomas H
Published: July 2016

Previous stable isotope studies of modern and archaeological faunal samples from sites around Lake Mývatn, within the Mývatnssveit region of northeast Iceland, revealed that an overlap existed between the δ15N ranges of terrestrial herbivores and freshwater fish, while freshwater biota displayed δ13C values that were comparable with marine resources. Therefore, within this specific ecosystem, the separation of terrestrial herbivores, freshwater fish, and marine fish as components of human diet is complicated when only δ13C and δ15N are measured. δ34S measurements carried out within a previous study on animal bones from Skútustaoir, an early Viking age settlement on the south side of Lake Mývatn, showed that a clear offset existed between animals deriving their dietary resources from terrestrial, freshwater, and marine reservoirs. The present study focuses on δ13C, δ15N, and δ34S analyses and radiocarbon dating of human bone collagen from remains excavated from a churchyard at Hofstaoir, 5 km west of Lake Mývatn. The results demonstrate that a wide range of δ34S values exist within individuals, a pattern that must be the result of consumption of varying proportions of terrestrial-, freshwater-, and marine-based resources. For that proportion of the population with14C ages that apparently predate the well-established first human settlement of Iceland (landnám) circa AD 871 ± 2, this has enabled us to explain the reason for these anomalously old ages in terms of marine and/or freshwater14C reservoir effects.
Second Radiocarbon Intercomparison Program for the Chauvetpont d'Arc Cave, Ardèche, France
Authors: Quiles A , Valladas H , Geneste J-M , Clottes J , Baffler D , Berthier B , Brock F , Ramsey C Bronk , Delqué-Količ E , Dumoulin J-P , Hajdas I , Hippe K , Hodgins G W L , Hogg A , Jull A J T , Kaltnecker E , De Martino M , Oberlin C , Petchey F , Steier P , Synal H-A , van der Plicht J , Wild E M , Zazzo A
Published: July 2016

The Chauvet-Pont d'Arc Cave is one of the most important sites for the study of the earliest manifestations and development of prehistoric art at the beginning of the Upper Paleolithic. Different dating techniques have been performed thus far (AMS14C, U/Th TIMS,36Cl dating) to model the chronological framework of this decorated cave. The cave yielded several large charcoal fragments, which enabled the opportunity for obtaining multiple dates; thus, a First Radiocarbon Intercomparison Program (FIP) was initiated in 2004 using three charcoal pieces. The FIP demonstrated that those cross-dated samples belonged to a time period associated with the first human occupation. One of the statistical interests of an intercomparison program is to reduce the uncertainty on the sample age; thus, to further assess the accuracy of the chronological framework, the Second Intercomparison Program (SIP) involving 10 international14C laboratories was carried out on two pieces of charcoal found inside two hearth structures of the Galerie des Mégacéros. Each laboratory used its own pretreatment and AMS facilities. In total, 21 and 22 measurements were performed, respectively, which yielded consistent results averaging ∼32 ka BP. Two strategies have currently been developed to identify statistical outliers and to deal with them; both lead to quasi-identical calibrated combined densities. Finally, the new results were compared with those of the FIP, leading to the important conclusion that five different samples from at least three different hearth structures give really tightened temporal densities, associated with one short human occupation in the Galerie des Mégacéros.
Simulations and Outputs
Authors: Griffiths Seren
Published: July 2016

Bayesian analysis is now routinely applied for the construction of site-specific stratigraphic chronological models. Other approaches have analyzed the chronology of phases of archaeological activity across regions. The available radiocarbon results—the nature of the samples and their associations—provide the basis for what chronological questions it is possible to address for any site or region. In dealing with regional analyses, due consideration must be made of data selection. While data selection might be a relatively self-evident consideration in the analysis of a site chronology, working with data from a larger region poses a number of specific data selection issues. Robust association between dated samples and a particular type of diagnostic material culture or site may provide one means of producing regional chronologies. However, if the activity under investigation includes a number of different cultural traits, which are related but with each having a slightly different chronological currency, defining the temporal end of data selection becomes more problematic. This article presents one approach, using a case study from the British Mesolithic-Neolithic transition, with 880 simulation OxCal models used to investigate the effect of variously defining the end of a regional archaeological phase. The results emphasize that for a regional case study, sensitivity analysis may provide a useful tool to ensure representative models; the study also highlights the importance of comparing multiple model posteriors.
Bridging the Gaps in Tree-Ring Records: Creating a High-Resolution Dendrochronological Network for Southeastern Europe
Authors: Ważny Tomasz , Lorentzen Brita , Köse Nesibe , Akkemik Ünal , Boltryk Yurij , Güner Tuncay , Kyncl Josef , Kyncl Tomaš , Nechita Constantin , Sagaydak Severin , Vasileva Jeni Kamenova
Published: July 2016

Dendrochronological research in North-Central Europe and the East Mediterranean has produced networks of long regional oak (Quercussp.) reference chronologies that have been instrumental in dating, provenancing, and paleoclimate research applications. However, until now these two important tree-ring networks have not been successfully linked. Oak forests and historical/archaeological sites in southeastern Europe provide the key for linking the North-Central European and East Mediterranean tree-ring networks, but previous dendrochronological research in this region has been largely absent. This article presents the initial results of a project, in which we have built oak tree-ring chronologies from forest sites and historical/archaeological sites along a north-south transect between Poland and northwestern Turkey, with the aim of linking the North-Central European and East Mediterranean tree-ring networks and creating a new pan-European oak data set for dendrochronological dating and paleoclimatic reconstruction. Correlation among tree-ring chronologies and the spatial distribution of their teleconnections are evaluated. The southeastern European chronologies provide a solid bridge between both major European dendrochronological networks. The results indicate that a dense network of chronologies is the key for bridging spatial and temporal gaps in tree-ring records. Dendrochronological sampling should be intensively continued in southeastern Europe because resources for building long oak chronologies in the region are rapidly disappearing.
1.1. The Galactic bulge
Authors: Rich R. Michael
Published: July 2016

I review current work on the Galactic bulge, with emphasis on issues that may connect to the environment of the Galactic Center. There is growing evidence that the field population of the bulge at RGC > 500pc is as old as the metal rich Galactic center globular clusters, and that field and clusters have the same spatial and metallicity distribution. We suggest that by analogy, extragalactic metal rich cluster systems, which also tend to follow the spheroid light, are old. On the other hand, there has been long standing evidence for an age gradient toward the Galactic center, and recent observations confirm without doubt that there is active star formation there. If a long-lived bar has been funneling gas (and inducing star formtion) in the central 100 pc, the star formation history there will be complicated and interesting.
1.2. The bulge stellar population in M31
Authors: Jablonka P. , Bridges T. , Meylan G. , Sarajedini A.
Published: July 2016

We obtained WFPC2 high spatial resolution images, in filters F555W and F814W, of a few fields in the bulge of M31. Two are located SW along the major axis of M31, respectively at 6.1 and 3.2 arcmin of the galaxy nucleus; another is located NE along the major axis at 3.7 arcmin. Adopting 1 arcmin = 250 pc from Rich & Mighell (1995), these separations correspond to projected distances of about 1.55, 0.80, and 0.92 kpc, respectively. We present here some of our results after analysis of the I; V – I colour magnitude diagrams of the bulge stellar population, which are part of an extensive work to be published elsewhere (Jablonka et al. 1997).
1.5. SiO maser sources in the Galactic bulge and a kinematic signature of the bar structure
Authors: Deguchi S.
Published: July 2016

We are studying the kinematic structure of our Galaxy by detecting SiO maser lines around 43 GHz with the Nobeyama 45-m telescope. Till today, about 500 IRAS sources (AGB stars) in the central region of the Galaxy are observed and the radial velocities of about 300 detected sources are obtained. The longitude-velocity map of SiO sources clearly shows a presence of forbidden regions (holes) which are located at the same positions of HI and CO holes. The presence of holes is interpreted as a streaming motions of stars due to a bar structure of the Galactic bulge
1.7. Secular dynamical evolution of spiral galaxies and the formation of galactic bulges
Authors: Zhang Xiaolei
Published: July 2016

We show that a recently discovered spiral-induced radial mass accretion process could account for the formation of the Galactic Bulge in a Hubble time. This process is thus expected to be important in the formation of bulges in spiral galaxies, and in the secular evolution of galaxies along the Hubble sequence from late to earlier types.
1.10. The effects of the disk field on the bulge surface brightness
Authors: Andredakis Y.C. , Sanders R.H.
Published: July 2016

After the classical description of bulges by a de Vaucouleurs profile was found to be inadequate, a generalized profile, Sersic's law, was used successfully to describe the surface brightness:
(Andredakis et al. 1994 (APB95)). The exponent n was found to vary systematically with the morphological type of the galaxy, from n = 4 for the bulges of S0s to n = 2 for intermediate type spirals and n = 1 (pure exponential) for the late types. (APB95, de Jong 1996). This has been confirmed also by the kinematics (Heraudeau et al 1996). This variation of n has been interpreted in two ways: (i) As the effect of the disk forming around an already developed bulge (APB95) and (ii) as evidence that the bulge originated from secular processes in the galaxy, after the disk was formed (Courteau et al. 1996). This needs to be resolved.
1.12. Structure of the inner galactic disk and the bulge - first results
Authors: Feltzing S.
Published: July 2016

Is there an age and/or a metallicity gradient in the Bulge? This is a notoriously difficult question because of the well known age-metallicity-distance degeneracy in colour magnitude diagrams (CMD) as well as the severe crowding and large reddening towards the Galactic Bulge. The current observational data on the bulge in our galaxy and bulges in other spiral galaxies point in disparate directions, that is evidence for both early (e.g. existence of very old halo and bulge globular clusters) and late formation (e.g. Sgr dSph and bar instabilities) can be found as well as the existence and non-existence of metallicity gradients (for a review of the observational status see Wyse, Gilmore & Franx 1997). We here present the CMDs for two fields, Baade's window and SGR-I, Fig.1c and d. Both these regions have low extinction. To determine the age and metallicity for these stars we compare the CMDs with CMDs of globular clusters, also observed with WFPC2, of known metallicity and age, Fig.1a and b. This method enables us to work entirely in the in-flight magnitude system of WFPC2 and there is no need for transformations to standard colours and magnitudes, something which is not straight forward for WFPC2 passbands.
2.6. Resolved near-IR survey of the inner Galaxy
Authors: Unavane M. , Gilmore G.
Published: July 2016

The analysis of resolved DENIS (Deep Near Infra Red Survey of the Southern Sky) I,J and K band data shows good evidence (≳ 3σ) in the J and K band number counts to support the existence of a kiloparsec-scale bar with its major axis in the first quadrant. A star by star dereddening of this K data combined with supplementary nbL band data (3.6μm) gives number count contrasts consistent with low angle (≲ 20 degrees) bar models in the literature.
2.14. Stellar and ionized gas-velocity fields in the central regions of a sample of galaxies
Authors: del Burgo C. , Arribas S. , Mediavilla E. , García-Lorenzo B.
Published: July 2016

We present the velocity fields for the ionized gas and the stars obtained from 2D fibre spectroscopy in the central regions of a sample of active (NGC 985, NGC 1052, NGC 6500) and non-active (M31, M32) galaxies.
3.3. Circumnuclear regions of active and non-active barred galaxies
Authors: Knapen J.H.
Published: July 2016

I discuss the role of galactic bars in the fuelling of (circum)nuclear activity. Since the majority of all galaxies are barred, the presence of a bar in a Seyfert galaxy cannot be the sole reason for their activity, although it appears to be a necessary condition for activity. Two options for further work are being explored, high-resolution near-infrared imaging of samples of active and non-active galaxies, and detailed case studies of selected galaxy cores.
3.5. High-resolution ISOCAM view of nuclear and circumnuclear starbursts in barred galaxies
Authors: Friedli D. , Wozniak H. , Martinet L. , Pfenniger D.
Published: July 2016

Non-axisymmetric gravitational potentials are likely to play an important role in generating central activity in galaxies, i.e. starbursts and/or active galactic nuclei (AGN). For instance, the often observed secondary bars embedded in larger, primary, ones (Friedli & Martinet 1993; Wozniak et al. 1995; Friedli et al. 1996) might play a key role in feeding AGN, by accreting gas down to the centre at scales of a few parsecs. On the other hand, the frequent presence of a nuclear ring of star formation located between both bars indicates that double-barred galaxies are intimately linked to the formation of some circumnuclear starbursts. This type of galaxies might give useful clues to the connection between starbursts and AGN.

Below, as part of a larger sample of nearby barred galaxies (Wozniak et al. 1997a) being taken by ISOCAM on board of the ISO satellite, we briefly discuss the characteristics of the circumnuclear mid-infrared (MIR) emission of two double-barred galaxies, namely NGC 4321 (M100) and NGC 1097. The observations were done using LW2 (5–8.5μm) and LW3 (12–18μm) broad band filters at the 1.5″ px−1 PFOV.
3.14. Infrared variations of active galaxies: what they tell us
Authors: Glass I.S.
Published: July 2016

Little is known about the long-term infrared variations of Seyfert galaxies. Are they large or small, fast or slow, regular or irregular? Do they possess variable components hidden at visible wavelengths? Can their variational time-scales give us information about activity on sub-milliarcsecond spatial scales? Do the infrared measurements show well-defined flux variation gradients? Is the infrared flux delayed with respect to changes in the output of the central engine? And do the infrared variability studies support the “Unified Model”?
3.15. Narrow-band imaging of the nuclear region of the Seyfert galaxy NGC1068
Authors: Ishigaki T. , Ohtani H. , Hayashi T. , Ozaki S. , Hattori T. , Sugai H. , Sasaki M. , Aoki K. , Yoshida M. , Watanabe E.
Published: July 2016

A narrow-band imaging observation of the Seyfert galaxy NGC1068 was made in the Fabry-Perot mode of the Kyoto 3D Spectrograph attached to the 188cm telescope of the Okayama Astrophysical Observatory. We observed at wavelengths of Hα, [S ii]λ6716, [S ii]λ6731 and adjacent continua of the respective lines with a “tunable filter”, i.e. a gap-scanning etalon with a spectral resolution of 20 Å.
3.20. OH/IR stars as signposts for ancient starburst activity in the Galactic center
Authors: Sjouwerman L.O. , Habing H.J. , van Langevelde H.J. , Lindqvist M. , Winnberg A.
Published: July 2016

We have surveyed the Galactic center (GC) for OH/IR stars, evolved late-type stars of different masses - and thus ages - in a short-lived stage of heavy mass-loss. By observing the 1612 MHz OH masers generated in their circumstellar shells, it is found that a considerable fraction of these OH/IR stars has the same high-valued shell expansion velocity of 19 km s−1.
3.27. Millimeter-wave continuum observation of galaxies
Authors: Matsuo H. , Kuno N. , Vila-Vilaro B. , Kashihara H. , Kawabata T.
Published: July 2016

Continuum observation of galaxies in millimeter-wave gives informations on dust emission from molecular clouds, free-free emission from HII region and synchrotron emission from SNR and diffuse component. The free-free emission can be observed only at millimeter-wave frequencies and their emission is optically thin, it can be a good indicator of their star-formation activities.
3.28. Three-dimensional distribution of the nuclear mirrors in NGC 1068
Authors: Kishimoto Makoto
Published: July 2016

Recently, the HST imaging observations have revealed that the central arc second region in NGC 1068 has a clumpy structure (Macchetto et al., 1994) and the HST UV imaging polarimetry has revealed the centrosymmetric pattern of the position angles of polarization (Capetti et al., 1995), which indicates that the medium in this region is actually scattering the radiation from a small source, in accordance with the unified model of active galactic nuclei (Antonucci & Miller, 1985).
4.1. Radio continuum and molecular gas in the Galactic center: large-scale structures
Authors: Sofue Yoshiaki
Published: July 2016

The radio emission from the Galactic Center is a mixture of thermal (free-free) and non-thermal (synchrotron) emissions (Fig. 1a). However, the spectral index in the central 3° region is flat almost everywhere (Sofue 1985), even in regions where strong linear polarization is detected. Therefore, a flat spectrum observed near the galactic center can no longer be taken as an indicator of thermal emission.
4.5. Sub-mm [C I] and CO observations of molecular clouds presumably interacting by the G359.54+0.18 nonthermal filaments
Authors: Staguhn J. , Stutzki J. , Balm S. P. , Stark A. A. , Lane A. P.
Published: July 2016

We have investigated the physical properties of molecular clouds which are presumably interacting with the G359.54+0.18 Nonthermal Filaments and an associated H ii region east of the filaments (Staguhn et al., 1996). The sub-mm spectra of 12CO(3-2) were observed with the KOSMA 3 m telescope, while the 490 GHz [C i] 3P1 →3P0 observations were made with the AST/RO 1.7 m sub-mm telescope. Fig. 1 shows channel maps of the integrated CO and [C i] line intensities in the velocity range of the recombination line observed towards the nearby H ii region. This H ii region is traced by the VLA 5 GHz continuum observations which are shown as contours in the central parts of the maps. The G359.54+0.18 Nonthermal Filaments, situated further to the west, appear to be morphologically associated with the H ii region. The [C i] emission of the molecular cloud east of the filaments which is kinematically linked to the H ii region is anti-correlated with the molecular line emission over a large angular extent. It is unlikely that the large morphological differences between [C i] and CO in this region can be explained exclusively by a high abundance of neutral carbon in the surface regions of dense molecular clumps, as is usually the case in PDR regions near the Sun.
4.10. Statistical properties of dense molecular clouds in the Galactic center region
Authors: Miyazaki Atsushi , Tsuboi Masato
Published: July 2016

Data : We used the Galactic center region survey data in CS J=1-0 with the Nobeyama 45-m telescope (Tsuboi, Handa, and Ukita 1997).

Cloud Definition : We identified molecular clumps in the positive longitude region of about ∼1deg2 (+0°10′ < l< + 1°42′ and −25′ < b< +25′) within all survey region.
4.14. Molecular shell formation by supernova remnants in the Galactic center—what we learn from the case of W44
Authors: Seta Masumichi , Winnewisser Gisbert , Hasegawa Tetsuo , White Glenn J. , Oka Tomoharu
Published: July 2016

Recent high resolution CO images of the Galactic center (GC) molecular clouds reveal many arc and/or shell structures (Oka et al. 1997). A considerable fraction of them may most probably be formed by an interaction between supernova remnants (SNRs) and molecular clouds. Studies of such cases in less confused areas are needed to clarify this picture. The SNR W44 is a good place for examining the SNR induced shell formation scenario.
5.1. Molecular gas in luminous galactic nuclei
Authors: Scoville N. Z. , Baker A. J.
Published: July 2016

In the last five years, millimeter-wave interferometry has clearly shown the existence of enormous masses (109–1010 M⊙) of molecular gas concentrated in the nuclear regions (R < 500 pc) of many luminous and ultra-luminous infrared galaxies. In these systems, molecular gas is an obvious source of fuel for nuclear starbursts and active galactic nuclei (AGN). For nearer, lower-luminosity systems there exists less systematic characterization of either the properties or the structure of the nuclear gas. Here we review recent results on the molecular gas in the nuclei of two near, lower-luminosity systems (M51 and NGC 1068) and contrast these results with those for the best studied ultra-luminous IRAS galaxy, Arp 220. For all three galaxies, there now exists CO(2–1) interferometry at high resolution which reveals, for the first time, disks of extremely dense, highly excited gas on scales of 50-300 pc. These structures vary in their levels of axisymmetry, thickness, and clumpiness. However, they share the ability to extinguish optical and near-infrared emission from active or stellar nuclei and perhaps to collimate radio jets and ionized outflows. Within the nuclear regions of these three galaxies, the molecular gas constitutes 10-50% of the total mass, with the most luminous systems having the highest gas mass-fractions.
5.3. NRO/OVRO CO(1-0) survey: central regions of nearby spiral galaxies
Authors: Sakamoto K. , Okumura S. K. , Ishizuki S. , Scoville N. Z.
Published: July 2016

We have done a CO(1-0) imaging survey of the central regions of nearby spiral galaxies using the Nobeyama and Owens Valley Millimeter Arrays. The survey aims to reveal the nuclear gas properties in normal galaxies that have been paid relatively little attention compared to Seyferts, mergers, and ultraluminous IRAS galaxies. The sample consists of 20 galaxies that meet the following criteria: (1) i < 70° (2) δ > +5° (3) ICOdV ≥ 10 K(T∗A)km s−1 in the FCRAO Extragalactic CO Survey (4) no evidence of significant perturbation (e.g. merging). No selection was made on the basis of nuclear activity or IRAS data. The average distance of the galaxies is 15 Mpc and the average linear resolution is 300 pc.
5.4. New high-resolution observations of molecular gas towards the center of spiral galaxies
Authors: Garcia-Burillo S.
Published: July 2016

We discuss the major results from a study of the molecular gas distribution and dynamics in the nuclear disks (ND) of a limited sample of nearby spirals: NGC891, NGC5907, NGC4565, NGC4013, NGC4321, M82, NGC3626 and NGC3593. The main objective is to search for observational evidences of secular evolution along the Hubble sequence in spirals and to study the specific role of bars in the process.
5.5. The detection of a gas-rich bar in the interacting galaxy UGC 2855
Authors: Hüttemeister S. , Aalto S. , Wall W. F.
Published: July 2016

Bars fuel the prolific star formation rate in many Starburst galaxies. They provide a mechanism for feeding gas into the nuclei as well as a laboratory for the study of molecular gas that is unbound and diffuse due to tidal strain and cloud collisions. A large percentage of galaxies show a stellar bar which is, however, in most cases almost devoid of (molecular) gas, except in the central region. Thus, long gaseous bars are rare and transient phenomena.
5.14. NMA survey of HCN and CO emission from nearby active galaxies
Authors: Kotaro Kohno , Ryohei Kawabe , Kazushi Sakamoto , Sumio Ishizuki , Vila-Vilaro Baltasar
Published: July 2016

In order to study the spatial variation of molecular gas properties and their relation to the nuclear activities of galaxies, we have conducted an imaging survey of HCN(1-0) and CO(1-0) emission from nearby active galaxies with the Nobeyama Millimeter Array. Here we present the results of three galaxies, NGC 3504 (Starburst nucleus), NGC 4736 (Post-Starburst nucleus), and NGC 6951 (Seyfert nucleus with a circumnuclear star-forming ring).

In the observations of these three galaxies, we find that (1) the HCN distribution is significantly different from that of CO, and that (2) the HCN emission spatially correlates better with the massive star-forming region than CO emission (Figure 1, 2(a), and 2(b)). For instance, in the Post-Starburst nucleus of NGC 4736, we find a remarkable decrease of the HCN emission, despite of strong CO nuclear concentration. The upper limit (2σ) of the integrated intensity ratio I(HCN)/I(CO) within the central r < 150 pc region is 0.04, which is surprisingly low compared with the value in other galactic nucleus (cf. ratio = 0.08 within r < 300 pc in Milky Way, Jackson et al. 1996, ApJ, 456, 91). Presumably the dense molecular gas must have been consumed by a past starburst event in the nucleus. These results suggest a tight correlation between the gas density measured by the I(HCN)/I(CO) ratio and the star-forming activities in the central region of galaxies.

It seems that there exist a spatial anti-correlation between the I(HCN)/ I(CO) ratio and the gas velocity dispersion in NGC 6951 (Figure 2(c)). The ratio is not enhanced in the CO twin peaks which are interpreted as shock regions due to gas orbit crowding. These imply the importance of gravitational instability on the formation of dense molecular gas and successive massive starformation in this region.
6.3. Physical conditions of the gas in the center of the nearby spiral galaxy IC 342
Authors: Turner J. L.
Published: July 2016

One of our nearest neighbors is a large spiral galaxy with abundant molecular gas in its nucleus. IC 342, a face-on Scd galaxy at a distance of 1.8 Mpc, is close enough to give us a view of individual molecular clouds with millimeter interferometry. The CO distribution in the nucleus of IC 342 consists of two very open spiral arms (Lo et al. 1984; Ishizuki et al. 1990) that continue to within 50 pc of the dynamical center (Turner & Hurt 1992). The total extent of the nuclear “mini-spiral” is ~ 500 pc. Corresponding arms are observed in Hα (J.S. Young, private comm.). However, the Hα arms are systematically offset by 50-100 pc from the CO arms (Turner & Hurt 1992). The offset of the Hα arms to the outer, leading edge of the CO arms is consistent with a picture of density wave-induced star formation in the arms (Turner & Hurt 1992). Energy dissipation and angular momentum transfer in spiral arms is believed to drive a slow drift of gas inward; if this is the case, the molecular “mini-spiral” in IC 342 is short-lived, and will probably no longer exist in another 108 years.
6.4. Formation and evolution of gaseous bars
Authors: Friedli D.
Published: July 2016

Although numerous gaseous bars are observed, they seem to be much less common than stellar bars. This might be due to an observational bias, but gaseous bars could also be difficult to form and/or have short lifetimes. Gas morphology is strongly dependent on the resolution and the considered scale. A true bar-like shape (Maffei 2) should not be confused with either ring-like plus open arms (IC 342), or “twin peaks” (NGC 3351) morphologies. Typical observed gaseous bar characteristics are 2ag ~ 1 kpc, and Mg ~ 0.1–0.3Mdyn inside a few 100 pc. Below, three mechanisms of gaseous bar formation, as well as their evolution, are briefly discussed.
6.8. A multi wavelength study of the circumnuclear region of NGC 1365
Authors: Kristen H. , Sandqvist Aa. , Lindblad P.O.
Published: July 2016

The nuclear region of the supergiant barred spiral galaxy NGC 1365 contains bright “hot spots”, as seen at optical wavelengths, as well as a number of non-thermal radio continuum sources, some of which remain unresolved at 0.25” × 0.10” resolution (Sandqvist et al. 1995, A&A 295, 585).

The distribution of [OIII] λ5007 emission from the nuclear region supports the scenario of an [OIII] cone emanating from the Seyfert nucleus. The velocity field of the high excitation gas in the cone has been modeled by Hjelm & Lindblad (1996, A&A 305, 727) in terms of an accelerated bipolar conical outflow. Such conical or biconical high-excitation emission-line structures extending from the position of the nucleus are found in several active galactic nuclei.
6.9. Interpreting the main HI and CO ℓ–V features in the Galactic bar from self-consistent stellar and gas dynamical models
Authors: Fux R.
Published: July 2016

We propose a new picture accounting for the dominant features in the observed ℓ−V distribution of the Milky Way gas within the central few kpcs, based on the gas flow in two self-consistent and symmetry-free barred dynamical models. These models are snapshots selected from high resolution 3D N-body and SPH simulations with 4 × 106 stellar and dark particles and 1.5 × 105 gas particles, and with initial conditions adapted from Fux (1997). The main results are shown in figure 1. In both models, the inclination angle of the bar relative to the Sun-Galactic centre line is 25°, the corotation radius close to 4.4 kpc and the sound speed of the gas 10 km s−1.
6.10. The dust lanes of the barred galaxy NGC 5383
Authors: Ann H.B. , Kim J.M.
Published: July 2016

NGC 5383 is a barred galaxy of type (R′)SB(rs)b: pec with well developed dust lanes which provide valuable information about the dynamics of the galaxy. It is well known that dust lanes in barred spiral galaxies represent the loci of shock fronts which are caused by the gas inflow driven by bar potential (Athanassoula 1992). However, detailed morphology of dust lanes depends on the distribution of masses in bulge, disk, and bar as well as bar pattern speed. We conducted a UBVRI and Hα surface photometry and SPH simulations for NGC 5383 to investigate the relation between the morphology of dust lanes and the dynamical properties of barred galaxies.
7.4. The 3.4 micron absorption in the Galactic center sources
Authors: Nagata T.
Published: July 2016

The 3.4μm absorption feature, first detected in the Galactic center source IRS7 (Soifer et al., 1976), has been observed in other Galactic center sources IRS3, IRS12 (McFadzean et al., 1989), and IRS6E (Pendleton et al., 1994). This feature is regarded as characteristic of dust in the diffuse interstellar medium, and attributed to C-H stretching vibrations. Several objects in the lines of sight other than the Galactic center is now known to have the feature (Sandford et al. 1995 and references therein; Imanishi et al. 1996). The absorption depths per unit visual extinction τ3.4/AV for these sources are compared with those for the Galactic center sources, and they are thought to increase near the Galactic center. However, the “Galactic center” sources are all in the central parsec cluster, and the features observed in them may be only representative of interstellar medium local to the central parsec, not the general diffuse interstellar medium of the inner Galaxy. In this paper, we report the 3.4μm absorption feature detected in near-infrared sources within 1° of the Galactic center.