"Brought under the law of the land" : the history, demography and geography of crossculturalism in early modern Izmir, and the Köprülü Project of 1678

The port-city of Izmir (old Smyrna) plays a crucial role in modern world history. From the 1570s, that city became subjected to European mercantile interests and quickly developed into the main conductor of an irreversible European takeover of the Ottoman economy – the structural basis of a centuries-long decline of the once-mighty Ottoman Empire. Or, so the historical consensus dictates. The problem is that this consensus has been constructed over a conspicuous shortage of sources by an overreliance on grand theories paired with a fundamental misunderstanding of the Ottoman (political, legal, economic and social) system and its solutions to the challenges of the times. This study wants to uncover and question the teleological (mostly Eurocentric, oftentimes triumphalist) historiography of city, empire and world systems that have resulted. In its stead, it lays the foundations of a historiography that restores 17th-century Izmir (and perhaps early-modern Ottoman civilization) to the role of an active and autonomous participant-alternative to Europe’s expanding world system.Middle Eastern Studie

Delayed Photoionization Feedback in a Super Star Cluster in SBS0335-052E

SBS0335-052 is a well studied Blue Compact Dwarf galaxy with one of the lowest metallicities of any known galaxy. It also contains 6 previously identified Super Star Clusters. We combine archival HST NICMOS images in the Pa alpha line and the 1.6 micron continuum of the eastern component, SBS0335-052E, with other space and ground based data to perform a multi-wavelength analysis of the super star clusters. We concentrate on the southern most clusters, designated S1 and S2, which appear to be the youngest clusters and are the strongest emitters of Pa alpha, radio, and x-ray flux. Our analysis leads to a possible model for S1 and perhaps S2 as a cluster of very young, massive stars with strong stellar winds. The wind density can be high enough to absorb the majority of ionizing photons within less than 1000 AU of the stars, creating very compact HII regions that emit optically thick radiation at radio wavelengths. These winds would then effectively quench the photoionizing flux very close to the stars. This can delay the onset of negative feedback by photoionization and photodissociation on star formation in the clusters. This is significant since SBS0335-052E resembles the conditions that were probably common for high redshift star formation in galaxies near the epoch of reionization.Comment: Accepted for publication in the Astrophysical Journa

Extremely broad radio recombination maser lines toward the high-velocity ionized jet in Cepheus A HW2

We present the first detection of the H40a, H34a and H31a radio recombination lines (RRLs) at millimeter wavelengths toward the high-velocity, ionized jet in the Cepheus A HW2 star forming region. From our single-dish and interferometric observations, we find that the measured RRLs show extremely broad asymmetric line profiles with zero-intensity linewidths of ~1100 kms-1. From the linewidths, we estimate a terminal velocity for the ionized gas in the jet of >500 kms-1, consistent with that obtained from the proper motions of the HW2 radio jet. The total integrated line-to-continuum flux ratios of the H40a, H34a and H31a lines are 43, 229 and 280 kms-1, clearly deviating from LTE predictions. These ratios are very similar to those observed for the RRL maser toward MWC349A, suggesting that the intensities of the RRLs toward HW2 are affected by maser emission. Our radiative transfer modeling of the RRLs shows that their asymmetric profiles could be explained by maser emission arising from a bi-conical radio jet with a semi-aperture angle of 18 deg, electron density distribution varying as r^(-2.11) and turbulent and expanding wind velocities of 60 and 500 kms-1.Comment: 6 pages, 2 figures, 3 tables, accepted for publication in ApJ

MSX versus IRAS Two-Color Diagrams and the CSE-Sequence of Oxygen-Rich Late-Type Stars

We present MSX two-color diagrams that can be used to characterize circumstellar environments of sources with good quality MSX colors in terms of IRAS color regions for oxygen-rich stars. With these diagrams we aim to provide a new tool that can be used to study circumstellar environments and to improve detection rates for targeted surveys for circumstellar maser emission similar to the IRAS two-color diagram. This new tool is especially useful for regions in the sky where IRAS was confused, in particular in the Galactic plane and bulge region. Unfortunately, using MSX colors alone does not allow to distinguish between carbon-rich and oxygen-rich objects. An application of this tool on 86 GHz SiO masers shows that for this type of masers an instantaneous detection rate of 60% to 80% can be achieved if target sources are selected according to MSX color (region). Our investigations may have revealed an error in the MSX point source catalog version 2.3. That is, the photometry of the 21.3 $\mu$m (MSX E filter) band for most weak 8.28 $\mu$m (or MSX A filter) band sources seems off by about a factor two (0.5--1 magnitude too bright).Comment: accepted to Astrophysical Journal, 11 pages, 11 figs of which 1 in colo

The A-X infrared bands of Aluminum Oxide in stars: search and new detections

We describe a search for the A-X infrared bands of AlO with a view to better understand the characteristics of this radical. These bands are infrequently encountered in astronomical sources but surprisingly were very prominent in the spectra of two well-known, nova-like variables (V838 Mon and V4332 Sgr) thereby motivating us to explore the physical conditions necessary for their excitation. In this study, we present the detection of A-X bands in the spectra of 13 out of 17 stars, selected on the basis of their J-K colors as potential candidates for detection of these bands. The majority of the AlO detections are in AGB stars viz. 9 OH/IR stars, 2 Mira variables and 2 bright infrared sources. Our study shows that the A-X bands are fairly prevalent in sources with low temperature and O-rich environments. Interesting variation in strength of the AlO bands in one of the sources (IRAS 18530+0817) is reported and the cause for this is examined. Possible applications of the present study are discussed in terms of the role of AlO in alumina dust formation, the scope for estimating the radioactive $^{26}$Al content in AGB stars from the A-X bands, and providing possible targets for further mm/radio studies of AlO which has recently been discovered at millimeter wavelengths.Comment: To appear in Astrophysical Journal (Letters), 14 pages, 2 figure

A Parsec-Scale Study of the 5/15 GHz Spectral Indices of the Compact Radio Sources in M82

Observations of the starburst galaxy, M82, have been made with the VLA in its A-configuration at 15 GHz and MERLIN at 5 GHz enabling a spectral analysis of the compact radio structure on a scale of < 0.1'' (1.6 pc). Crucial to these observations was the inclusion of the Pie Town VLBA antenna, which increased the resolution of the VLA observations by a factor of ~2. A number of the weaker sources are shown to have thermal spectra and are identified as HII regions with emission measures ~10^7 cm^-6 pc. Some of the sources appear to be optically thick at 5 GHz implying even higher emission measures of ~10^8 cm^-6 pc. The number of compact radio sources in M82 whose origin has been determined is now 46, of which 30 are supernova related and the remaining 16 are HII regions. An additional 15 sources are noted, but have yet to be identified, meaning that the total number of compact sources in M82 is at least 61. Also, it is shown that the distribution of HII regions is correlated with the large-scale ionised gas distribution, but is different from the distribution of supernova remnants. In addition, the brightest HII region at (B1950) 09h 51m 42.21s +69 54' 59.2'' shows a spectral index gradient across its resolved structure which we attribute to the source becoming optically thick towards its centre.Comment: Accepted for publication in MNRAS. 15 pages, 9 figure

Dusty Wind-Blown Bubbles

Spurred by recent observations of 24 micron emission within wind-blown bubbles, we study the role that dust can play in such environments, and build an approximate model of a particular wind-blown bubble, `N49.' First, we model the observations with a dusty wind-blown bubble, and then ask whether dust could survive within N49 to its present age (estimated to be 5x10^5 to 10^6 years). We find that dust sputtering and especially dust-gas friction would imply relatively short timescales (t ~ 10^4 years) for dust survival in the wind-shocked region of the bubble. To explain the 24 micron emission, we postulate that the grains are replenished within the wind-blown bubble by destruction of embedded, dense cloudlets of ISM gas that have been over-run by the expanding wind-blown bubble. We calculate the ablation timescales for cloudlets within N49 and find approximate parameters for the embedded cloudlets that can replenish the dust; the parameters for the cloudlets are roughly similar to those observed in other nebula. Such dust will have an important effect on the bubble: including simple dust cooling in a wind-blown bubble model for N49, we find that the luminosity is higher by approximately a factor of six at a bubble age of about 10^4 years. At ages of 10^7 years, the energy contained in the bubble is lower by about a factor of eight if dust is included; if dust must be replenished within the bubble, the associated accompanying gas mass will also be very important to wind-blown bubble cooling and evolution. While more detailed models are certainly called for, this work illustrates the possible strong importance of dust in wind-blown bubbles, and is a first step toward models of dusty, wind-blown bubbles.Comment: 13 pages, 14 figures, Accepted to Ap

Excited-state OH Mainline Masers in AU Geminorum and NML Cygni

Excited-state OH maser emission has previously been reported in the circumstellar envelopes of only two evolved stars: the Mira star AU Geminorum and the hypergiant NML Cygni. We present Very Large Array (VLA) observations of the 1665, 1667, and excited-state 4750 MHz mainline OH transitions in AU Gem and Expanded Very Large Array (EVLA) observations of the excited-state 6030 and 6035 MHz OH mainline transitions in NML Cyg. We detect masers in both mainline transitions in AU Gem but no excited-state emission in either star. We conclude that the excited-state OH emission in AU Gem is either a transient phenomenon (such as for NML Cyg outlined below), or possibly an artifact in the data, and that the excited state OH emission in NML Cyg was generated by an episode of enhanced shock between the stellar mass-loss and an outflow of the Cyg OB2 association. With these single exceptions, it therefore appears that excited-state OH emission indeed should not be predicted nor observable in evolved stars as part of their normal structure or evolution.Comment: ApJ Letter, accepted, 4 pages, 2 figure